Quality control of masonry before the start of work. Inspection of brickwork. Technology and methods of making masonry

20.10.2023

Materials used

Masonry is a structure made of bricks or stones of regular shape laid on mortar in a certain order.

Clay hollow bricks have lower thermal conductivity compared to ordinary bricks, so they are advisably used for external and internal load-bearing walls.

Solution - a homogeneous mixture consisting of particles of a solute, a solvent and the products of their interaction

Material calculation

Brick calculation

To lay one row you will need 15 bricks

In a 1m high structure it is laid out

From a single brick 1000(65+12)=13

From one and a half 1000: (88+12)=10

Laying a boundary wall of one-and-a-half bricks for laying 10 rows will require 150 bricks

Calculation of mortar, the area of the mortar bed is calculated using the formula s=a*b s=1*047 the volume of mortar for laying one row is equal to v=s*h=047*003=00141 m3

Tools and accessories

01 trowel is a steel spatula with a curved handle used for leveling mortar and filling vertical seams, trimming excess mortar

02 hammer-pick, a metal hammer with a pointed head on one side and a wooden handle, used for chopping and chiseling bricks

03 mortar shovel for mixing the mortar and applying it to the masonry

Test instruments

Level 01 for checking the verticality and horizontality of the masonry

02 tape measure for linear measurements

03 plumb line, a galvanized weight weighing 02-1 kg on a cord, serves to check the laying of corners and to ensure the verticality of the masonry

Workplace organization

The masonry area, together with pallets with bricks, mortar boxes and scaffolds installed nearby, forms the mason's workplace. Proper organization of the workplace ensures high labor productivity.

When laying blind sections of walls, the mason's workplace has a width of 2.5...2.6 m and is divided into zones: - working (60...70 cm wide), where the mason moves during the masonry process; – storage (up to 1.6 m wide), where boxes with mortar alternate with pallets of bricks; – free (30...40 cm wide) for passage.

Brick and mortar are arranged in an alternating pattern

Masonry technology

The joint with cutting mortar ensures complete filling of the joints with mortar on the front surface. It is carried out on plastic solutions. The mortar bed is spread at a distance of 10-15mm from the edge of the wall. The brick is placed edgewise at an angle of 30 degrees at a distance of 5-8 cm from the previously laid one. After moving the brick to a horizontal position, it is pressed down with a trowel. at the same time, the excess mortar is trimmed with a trowel.

Preparing the base:

A rule with a level is applied to the base, irregularities are cut off or sealed with mortar.

The mooring line is being pulled.

To eliminate sagging of the mooring, lighthouse bricks are laid on the mortar every 4-5 m. The mooring is pressed from above with a brick installed on the lighthouse brick. The stretched mooring should protrude from the wall surface by 2-3cm; for this, the lighthouse bricks extend beyond the outer edge of the wall by 2-3cm.

For external miles, the mooring is installed on each row, and for internal ones after 3 rows. The bottom of the tensioned berth is located at the level of the top edge of the lighthouse brick.

Description of the row layout

Laying vertical wall boundaries of 1.5 bricks using a single-row seam dressing system. Each row uses ¾ bricks. In the first row, ¾ are laid with spoons, in the second with pokes.

The outer verst of the first row is laid out with a poke and the inner one with a spoon. The second row, the outer verst, is laid with a spoon, the inner one with a poke, this ensures an offset of ¼ of a brick, and the longitudinal seam is shifted by ½ of a brick. Starting from the third row, the sequence is repeated.

We carry out quality control at least twice per tier height.

MASONRY QUALITY CONTROL

The quality of the masonry must be checked throughout the entire process of its construction. The laying of walls and other stone structures should be carried out in accordance with the requirements of SNiP Sh-17-78, compliance with which ensures high quality of work.

During the construction of masonry, they monitor the compliance of the mortars and stones used with the project, the correctness of the seams and their quality, the verticality, horizontality and straightness of surfaces and corners.

During masonry, hidden work should be accepted according to acts drawn up by representatives of the construction organization and technical supervision of the customer, and acceptance of hidden work is carried out before the start of subsequent work. The following completed work and structural elements are subject to intermediate acceptance with the drawing up of reports - bases and foundations; waterproofing; installed fittings; areas of masonry in places where trusses, purlins and beams support; installation of embedded parts; securing cornices and balconies; expansion joints; protection against corrosion of steel elements and parts embedded in masonry; sealing the ends of purlins and beams in walls and pillars; supporting floor slabs on walls.

Deviations in the size and position of stone structures from the design ones should not exceed the permissible limits. Thus, the deviation of both the surfaces and corners of the masonry from the vertical is allowed no more than 10 mm per floor and no more than 30 mm over the entire height of the building. The deviation of masonry rows from the horizontal per 10 m in length should be no more than 20 mm. Irregularities on the surface of the walls, found when applying a 2 m long lath, should not be more than 10 mm for plastered surfaces and more than 5 mm for non-plastered surfaces. If deviations from the design dimensions are detected, as well as in the event of an increase in deviations compared to the permissible ones, the masonry must be dismantled and laid out again.

Masonry of irregularly shaped stones. Areas of use.

Rubble and rubble-concrete masonry is made from irregularly shaped stones.
Rubble stone is called masonry made of natural stones connected with mortar (Fig. IX.22, a). For rubble masonry they use: irregularly shaped stones - torn stones; bedded - stones with two parallel planes; cobblestones are stones that have a rounded shape.

Rubble masonry is used in the construction of foundations, basement walls, retaining walls, etc., and torn stones are placed in foundations and basement walls, and bedded stones are used in structures that bear significant vertical loads. It is also advisable to use sheet stones for the construction of walls of one- and low-story residential buildings. Rubble stone masonry is laid in rows, laying out corners, intersections and foundation walls, as well as milestone rows of larger stones.
Rubble masonry is produced in the following ways: “under the blade” or “under the gulf”.
Masonry “under the blade” is carried out on mortar in horizontal rows of stones selected in height with the seams bandaged using a two-row system. The thickness of each row is about 25 cm. The space between the milestone rows is filled with small stones and mortar. For masonry, a mortar with a mobility of 40...60 mm is used. The “under the shoulder” method is used to lay foundations, walls and pillars. In contrast to the laying of walls and pillars in foundations, the first row is laid dry from large bedded stones directly onto the mainland soil.

Bay masonry is used in the construction of low-rise buildings. When constructing ground walls, the masonry is laid in formwork, and when constructing foundations, it is laid in space with the vertical walls of the trenches. The stones are laid in horizontal rows 15...20 cm thick with the spaces between them carefully filled with small stones (crushed stone). Each row is filled with mortar with a mobility of 130...150 mm. The stones are laid without strictly bandaging the seams and making milestone rows, which is less labor-intensive and does not require highly qualified masons. However, when pouring, the solution does not always fill all the voids, which can reduce the density and load-bearing capacity of the masonry.

With a wall thickness of 0.6...0.7 m, rubble masonry is laid in tiers 1...1.2 m high. With an increase in wall thickness, the height of the tier decreases. Rubble masonry is made with the same tools as brick masonry, using the same devices. Additional tools are sledgehammers designed for breaking and chipping stones. As a rule, rubble masonry is carried out by a team of masons, consisting of 2 and 3 people. ("two" and "three"); When the masonry thickness is less than 80 cm, the work is performed by the “two” link, and when the masonry thickness is more than 80 cm, the “troika” link performs the work.

Rubble concrete masonry is a concrete mixture with rubble stones embedded in it (Fig. IX.22.6). For it, a slow-moving concrete mixture is used (with a cone draft of 3...5 cm) and stones no larger than 30 cm in size, but not more than 1/3 of the thickness of the structure. The masonry process consists of laying a layer of concrete mixture about 20 cm high and embedding rubble stone into it. Then the operation is repeated until the design height of the structure is reached. It is advisable to lay a covering layer of concrete mixture on top of the last layer of stones and compact it with surface vibrators.

To ensure the required density, solidity and strength of the masonry, the number of embedded stones should not exceed 50% of the volume of the structure being erected and the stones should be located at a distance of 4...5 cm from each other and from the outer surface of the structure. Rubble concrete masonry is carried out in formwork (in some cases, foundations can be built in space with the walls of the trench in tiers. The sequence of installing external and internal formwork and filling them is identical to similar operations when constructing walls made of monolithic concrete. The masonry is carried out by a team of masons-concrete workers of 8 people 2 people. they assemble and dismantle the formwork, 2 - prepare the stone and transport it to the laying site, 2 - lay the concrete mixture, 2 - embed the stones.

Rubble concrete masonry has greater strength and is less labor intensive compared to rubble masonry, but leads to an increase in cement consumption.

Features and technology of masonry in winter. Masonry quality control.

Masonry quality control

The quality of the masonry must meet certain standards that must be adhered to during the work process. Compliance with these standards will help to complete all masonry efficiently and accurately:

□ maximum deviation of walls from the designed thickness - 15 mm;

□ permissible deviation of the wall surface from the vertical - 10 mm;

□ it is allowed to deviate the rows of masonry from the horizontal by at least 7 mm per 5 m of length;

□ unevenness on the vertical surface of the wall when applying a 2 m long strip should be no more than 10 mm;

□ discrepancies in the marks of the upper surfaces of the walls are permissible within 10 mm;

□ the discrepancy in the thickness of masonry joints should not exceed: horizontal - +3 mm, -2 mm, vertical - +2 mm, -2 mm.

Carrying out rubble masonry allows for large errors in work:

□ according to the thickness of the structure - up to 30 mm in both directions - for the foundation and up to 20 mm - for the walls;

□ according to the marks of the supporting surfaces - 25 mm for the foundation, 15 mm for the walls;

□ according to the deviation of the surface of the wall masonry from the vertical - 20 mm;

□ according to the deviation of the rows of masonry from the horizontal by 5 m of the wall length - 15 mm for the foundation, 10 mm for the walls;

□ for unevenness on the vertical surface of the wall when applying a 2 m long strip - 15 mm.

The correct placement of 90 degree angles is monitored using a wooden triangle. The horizontality of the rows is checked using the rule on which the building level is placed. If an error is discovered during the laying process, it must be corrected during the laying of the next rows. The verticality of the walls is controlled using a plumb line at least twice for every meter of masonry.

Masonry in winter conditions

There is no doubt that all masonry work is best carried out in the summer or during the warm season, when the temperature outside is between 8-10 °C. But it happens that construction has to begin in winter. If you become familiar with the features of masonry in winter conditions, then frosts will no longer be an obstacle to successful construction and will not interfere with the implementation of your plans.

As a rule, as the temperature decreases, the hardening of the solution slows down. At an outside temperature of +5 °C, the solution hardens 3-4 times slower than at normal temperatures; at zero degrees the solution does not harden at all. At temperatures below zero, the masonry gains strength due to the freezing of the mortar. A garage built at sub-zero temperatures is not in danger of collapsing the foundation and masonry. With the onset of spring and rising temperatures, the masonry thaws, and the strength of the mortar will temporarily decrease. Gradually, the masonry mortar (2-6 days pass from the moment the outside temperature reaches above zero) hardens again, and the strength of the masonry increases.

The final strength of the masonry in this case will be lower than under normal temperature conditions, but for a garage this will be quite enough. It is recommended to strictly follow the masonry technology: all dressings must be carried out accurately, without deviations from the recommended schemes. This will help protect yourself from unexpected troubles when defrosting the building in the spring.

The technology for masonry work in winter is no different from that used under normal conditions. Bricks or stones should be cleared of ice and snow. The water for the solution should be heated to 800 °C, and the sand to 600 °C. It must be borne in mind that the solution has the property of quickly cooling and freezing, so you should not prepare it in large quantities. You can work with fresh solution for 30-40 minutes, after which a new portion is prepared. If you need to lay a mile, then the solution should be spread no more than two adjacent bricks; when making a backfill - no more than 6-7 bricks.

The recommended optimal solution temperature during operation is +15 °C. “In this case, the outside air temperature should be no lower than 200 ° C at a wind speed of 6 m/s. If the wind speed increases, then the temperature of the solution should be increased to +20 ° C. It is best to insulate the box for the solution; it is even better to build it with heating It is not recommended to use frozen or heated with hot water mortar for masonry.

The thickness of horizontal masonry joints should not exceed 12 mm, and vertical joints - 10 mm. Thickening of the joints may result in the mortar leaking out during thawing under the influence of load from the overlying part of the wall. With rapid freezing, the possibility of eliminating masonry errors is eliminated, so its quality must be monitored especially carefully. From time to time, the verticality of the walls should be checked. Thawing of inclined walls leads to an increase in tilt, which can destroy the masonry.

The gripping effect of the solution is enhanced with the help of so-called antifreeze chemical additives. Such additives include sodium nitrite, potash, their mixture, calcium nitrite with urea, as well as a mixture of calcium chloride and sodium chloride. The addition of these substances promotes partial setting of the solution in the cold and improves the adhesion of the solution to the stone after thawing. Additives should range from 1.5 to 15 percent of the cement weight, depending on the average daily air temperature. The setting of such mortars is much higher than that of cement, so you need to ensure that the mortar is used up before it begins to set. When preparing a solution, it should be mixed not with water, but with an aqueous solution of chemical additives. The filler in it will be ordinary sand; The cement must be of grade no lower than 300.

Masonry using such mortars has a significant drawback. Chemical additives that provide the antifreeze properties of the solution are hygroscopic substances that increase the humidity in the room. For this reason, so-called efflorescence can often be observed on the surface of walls built in winter.

Properly executed brickwork of walls determines the reliability and strength of the future structure. The criteria for assessing the quality of brickwork are regulated by SNiP for load-bearing and enclosing structures. Before starting construction work, you need to know what happens brickwork inspection

The building codes and regulations describe the following main points: brickwork inspections:

Permissible thickness of masonry joints:

10 mm (+5/-2 mm) for vertical seams;
12 mm (+3/-2 mm) for horizontal seams.

Permissible excess of deviations of the size of structures from the design value:

Building codes also regulate the entire process of bricklaying; it is according to them that the brickwork is checked:

The permissible deviation is no more than 10 mm for the marks of the supporting surfaces; no more than 20 mm displacement of the vertical axes of window openings; 10 mm displacement of the axes of the structure. It is impossible to weaken the structure with a hole or niche that is not provided for in the design.

Masonry surfaces and corners cannot deviate from the vertical more than:

by 10 mm for one floor;
by 15 mm for buildings up to two floors high. For accurate measurements you need

The verticality of the masonry is controlled by a plumb line and level twice on each tier, and the quality of the corners is checked using a square.

For every 10 meters of the wall, deviation of the masonry from the horizontal is allowed no more than 15 mm. Level and rule are tools for checking the horizontality of the rows (checked twice on each tier of brickwork).

Irregularities identified when applying a two-meter strip to vertical surfaces should not exceed 10 mm.

When multi-row dressing of seams, it is necessary to lay bonded rows under all prefabricated structures: the supporting part of the beams, floor slabs, balconies and purlins.

For window and door openings, it is necessary to install lintels according to the project.

The support area for the reinforced concrete slab must correspond to the dimensions specified in the project. In this case, the difference in elevations of two joined floor slabs cannot exceed 5 mm for a slab 4 meters long and 10 mm for longer slabs.

To tie with the masonry, which will be built later, in the place of the break, the masonry must be made in the form of a vertical or inclined groove. Every 2 meters of masonry, place 3 reinforcement bars in the seams.

A height of no more than 1.8 m is allowed for unreinforced brick partitions with a thickness of 12 cm, if they are not supported by ceilings or temporary fastenings.
Masonry in a waste area allows the following depth of joints unfilled with masonry mortar:
- in columns no more than 10 mm (vertical seams only);
- in other seams on the outside, no more than 15 mm.
Rules for masonry with reinforcement:

the thickness of the seam cannot exceed 16 mm, but when crossing the reinforcement, the thickness of the seam should be 4 mm greater than the sum of the diameters of the rods;
When manufacturing and laying meshes for transverse reinforcement of piers, it is necessary to ensure that at least two rods protrude and rest on the inner surface of the pier.

Before starting work, it is important to check the brand of brick and masonry mortar used, and also during the masonry process to monitor the correct dressing. After completion of construction, it is necessary to carry out. If you are not ready to do it yourself inspection of brickwork- contact the professionals!

They begin laying walls only after the workman or foreman checks: the completion of work on laying water supply inlets, district heating, gas pipelines and sewerage outlets; installation of floors above the basement, backfilling of pit cavities and installation of blind areas and drains. To drain surface water from the building; the quality of the wall material delivered to the construction site and the readiness of the work front.

The brickwork of walls and pillars is laid in horizontal rows, maintaining the verticality of the surfaces. Walls are laid using a multi-row or single-row (chain) seam bandaging system; pillars and narrow partitions no more than 1 m wide are laid using a three-row system. The master must ensure that masons use devices and tools to ensure the correctness of the masonry.

In order to maintain the exact direction of the masonry during the construction of the wall, the same thickness of the rows and the correctness of the masonry in the rows, orders are established (by plumb and level or by level) and a mooring cord is pulled along them. It is recommended to use inventory metal orders. A mooring made of twisted cord 2-3 mm thick is strengthened with a bracket.

The quality of the brickwork performed must be systematically monitored, for which the mason must use testing and measuring tools. The corners of the building are checked with a wooden square, the horizontality of the rows of brickwork on the walls is checked with a rule and a level at least twice on each tier of masonry. To do this, the rule is placed on the masonry, a level is placed on it and, having leveled it horizontally, the deviation of the masonry from the horizontal is determined. If it does not exceed the established tolerance, the deviation is eliminated during the laying of subsequent rows.

The verticality of wall surfaces and masonry corners is controlled by level and plumb line at least twice on each tier of masonry. If deviations are found that do not exceed the permissible ones, they are corrected when laying the next tier or floor. Deviations of the axes of structures, if they do not exceed the tolerances established by SNiP 3.03.01-87, are eliminated in the levels of interfloor ceilings.

Brickwork of walls, piers and pillars should begin and end with bonded rows. The butt rows should be laid under beams, purlins, mauerlats, at the level of edges of walls and pillars, as well as in protruding rows of masonry (for example, cornices, corbels). The bonded rows are laid out from whole bricks.

The most loaded parts in a building's structure are pillars and piers less than 2.5 bricks wide, and therefore they should be laid out of selected whole bricks. Half brick and broken brick can only be used in backfill masonry and lightly loaded structures (on sections of walls under windows, when filling frame walls).

The workman or craftsman is obliged to ensure that the height of the facing ceramic brick corresponds to the height of the masonry material. In exceptional cases, when laying with ordinary single-row bricks, facing stones with a height of 140 mm are used. This combination is permissible only if red brick of plastic pressing is used as the main masonry material with a reduction in the load-bearing capacity of the masonry by 10%. This should be stated in the draft. It is not recommended to use sand-lime brick with dry-pressed brick.

Laying of walls at intersections, junctions or junctions should be done simultaneously, observing the correct dressing of the seams. In cases where the brickwork is being laid with gaps, the foreman or foreman must control the correctness of the inclined or vertical grooves and check for the presence of steel connections in the previously completed brickwork. Steel ties are placed at least every 2 m in height and always at the level of each floor. The ties usually have a length of at least 1 m from the junction corner and end with anchors.

It is necessary to periodically (twice per shift) check the thickness of the seams, for which five to six rows of brickwork are measured and the average seam thickness is calculated. For example, five rows of masonry wall are 395 mm, then the average height of one row of masonry will be 395:5 = 79 mm, and the average thickness of the seam will be 790:65 = 14 mm.

The average thickness of horizontal joints of brickwork within the height of the floor should be 12 mm, vertical joints - 10 mm. In this case, the thickness of individual horizontal seams should be no less than 10 and no more than 15 mm, and vertical joints should be no less than 8 and no more than 15 mm. Thickening of seams contrary to those provided for by the rules can only be allowed in cases specified by the project; in this case, the dimensions of thickened seams are indicated in the working drawings.

The correct filling of the joints with mortar is checked by removing individual bricks of the laid row in different places at least three times along the height of the floor.

When checking horizontal and transverse vertical joints of brick masonry walls, as well as longitudinal joints of brick masonry lintels and partitions less than 1 m wide, it is necessary to ensure that they are completely filled with mortar. In longitudinal joints of blind walls and piers with a width of 1 m or more, partial filling of the joints with mortar is allowed. In the pillars, all seams must be completely filled with mortar, which is checked by removing individual bricks of the laid row in different places (at least three times along the height of the floor). The depth of joints not filled with mortar on the side of the front surface when laying hollow areas is allowed no more than 15 mm in walls and no more than 10 mm (vertical joints only) in columns.

The maximum height of walls erected without reinforcement with floors or coverings should not exceed the values established by SNiP 3.03.01-87.

When producing brickwork in seismic areas, increased requirements should be placed on the quality of the stone wall materials and mortar used. The surfaces of stone, brick or block must be cleaned of dust before laying. In mortars intended for the construction of masonry, Portland cement should be used as a binder.

Before the start of masonry work, the construction laboratory determines the optimal relationship between the amount of pre-wetting of the local stone wall material and the water content of the mortar mixture. Solutions are used with high water-holding capacity (water separation no more than 2%). The use of cement mortars without plasticizers is not allowed.

Masonry of bricks and ceramic slotted stones is carried out in compliance with the following additional requirements: masonry of stone structures is erected to the full thickness of the structures in each row; horizontal, vertical, transverse and longitudinal joints of the masonry are filled completely with mortar with cutting of the mortar on the outer sides of the masonry; masonry walls in places of mutual abutment are erected simultaneously; The bonded rows of masonry, including backfill, are laid out of whole stone and brick; temporary (assembly) breaks in the masonry being erected end with an inclined groove and are located outside the places of structural reinforcement of the walls.

When reinforcing brickwork (pillars), it is necessary to ensure that the thickness of the seams in which the reinforcement is located exceeds the diameter of the reinforcement by at least 4 mm, while maintaining the average thickness of the seam for a given masonry. The diameter of the wire of the transverse mesh for masonry reinforcement is allowed to be no less than 3 and no more than 8 mm. When the wire diameter is more than 5 mm, a zigzag mesh should be used. The use of individual rods (laid mutually perpendicular in adjacent seams) instead of knitted or welded rectangular mesh or zigzag mesh is prohibited.

To control the placement of reinforcement when mesh reinforcement of pillars and piers, the ends of individual rods (at least two) in each mesh should be released from the horizontal joints of the masonry by 2-3 mm.

During the masonry process, the builder or craftsman must ensure that the methods of securing purlins, beams, decks and floor panels in walls and posts are consistent with the design. The ends of split purlins and beams resting on internal walls and pillars must be connected and embedded in the masonry; According to the design, reinforced concrete or metal pads are laid under the ends of the purlins and beams.

When laying ordinary or wedge lintels, you should use only selected whole bricks and use a mortar of grade 25 and higher. The lintels are embedded in the walls at a distance of at least 25 cm from the slope of the opening. Under the bottom row of bricks, stacked iron or steel wire with a diameter of 4-6 mm is placed in a layer of mortar at the rate of one rod with a cross-section of 0.2 cm2 for each part of the lintel half a brick thick, unless the design provides for stronger reinforcement.

When laying a cornice, the overhang of each row should not exceed 1/3 of the length of the brick, and the total extension of the cornice should not exceed half the thickness of the wall. Cornices with a large offset should be reinforced or made on reinforced concrete slabs, etc., strengthening them with anchors embedded in the masonry.

Brickwork of walls must be carried out in accordance with the requirements of SNiP 3.03.01-87. During the production of brickwork, acceptance is carried out according to the hidden work report. Hidden work subject to acceptance includes: completed waterproofing; installed fittings; areas of masonry in places where purlins and beams support; installation of embedded parts - connections, anchors, etc.; fastening cornices and balconies; protection against corrosion of steel elements and parts embedded in masonry; sealing the ends of purlins and beams in walls and pillars (presence of support plates, anchors and other necessary parts); sedimentary joints; supporting floor slabs on walls, etc.

Practical work No. 3

MASONRY QUALITY CONTROL

AND ACCEPTANCE OF COMPLETED WORK

WHEN CONSTRUCTION OF STONE STRUCTURES

Goal of the work: acquire the skills to monitor the quality of work performed during the construction of stone structures.

Material support:

educational and laboratory stand “Stone works”;

theodolite (GOST 10529) – 1 pc.;

level (GOST 10528) – 1 pc.;

geodetic slats – 2 pcs.;

as a rule, plumb line - 2 pcs.;

construction level – 2 pcs.;

metal ruler (GOST 427) – 2 pcs.;

laser rangefinder – 2 pcs.;

square (GOST 3749) – 2 pcs.;

tape measure (GOST 7502) – 2 pcs.

Basic provisions

Quality control during the laying process. The laying of walls and other brick structures should be carried out in accordance with the design in accordance with SNiP 3.03.01-87 “Load-bearing and enclosing structures. Rules for the production and acceptance of work,” compliance with the requirements of which ensures the necessary strength of the structures being erected and high quality of work.

During the work, it is necessary to monitor the compliance of the brands of brick and mortar with the working drawings, and also check the correctness of dressing and quality of masonry seams, verticality, horizontality and straightness of surfaces and corners, correct installation of embedded parts and connections, quality of masonry surfaces (pattern and jointing, selection of bricks for the outer verst of unplastered masonry with subsequent jointing).

In the production of brickworkin seismic areas increased demands should be placed on the quality of the stone wall materials and mortar used. The surfaces of stone, brick or block must be cleaned of dust before laying. In mortars intended for the construction of masonry, Portland cement should be used as a binder.

When accepting stone structures made in seismic areas, the device is additionally controlled:

reinforced belt at the level of the top of the foundations;

floor-by-floor antiseismic belts;

fastening thin walls and partitions to main walls, frames and ceilings;

strengthening stone walls by including monolithic and prefabricated reinforced concrete elements in the masonry;

anchoring of elements protruding above the attic floor, as well as the strength of adhesion of the mortar to the wall stone material.

To check the quality of masonry, the mason uses control and measuring tools (Fig. 2.1).

Rice. 2.1. Bricklayer's testing and measuring tool:A – plumb line;b – folding meter;V – roulette;G – square;d - level;e – wooden rule;and – rule made of aluminum sheet;i...l – templates for laying channels;m – angular order;(1 – cord;2 – mobile clamp;3 – duralumin arrangement;4 – holes for fastening the clamp;5 – clamping bolt;6 – rule for removing the order;7 – brackets with a clamping bolt handle)

Correct placement of corners buildings are checked with a wooden square.

Horizontality of rows controlled by the rule (planed wooden strip 1500...2000 mm long, cross-section 40×50 mm, placed on a row of bricks) and level at least twice for each meter of masonry height. To do this, the level is placed on a rule. If deviations do not exceed those established by the tolerance according to SNiP 3.03.01-87, then they are eliminated during subsequent laying.

Verticality of surfaces Andcorners masonry is checked by level and plumb at least twice for each meter of masonry height. Deviations that do not exceed the established tolerances should be corrected when laying the next tier.

The verticality of the edges and corners of masonry made of bricks and stones, the horizontality of its rows must be checked as the masonry progresses (every 0.5...0.6 m) with the elimination of detected deviations within the tier.

After finishing the laying of each floor, an instrumental check should be carried outhorizontality Andtop marks masonry, regardless of intermediate checks of the horizontalness of its rows.

Seam thickness are also checked periodically. To do this, measure five to six rows of masonry and determine the average thickness of the seam (for example, when measuring five rows of masonry, we got 400 mm, therefore, the thickness of one row is 80 mm, and the thickness of the seam is 80 - 65 = 15 mm).

The average thickness of horizontal joints of brickwork within the height of the floor should be 12 mm, vertical joints - 10 mm.
In this case, the thickness of individual vertical seams should be no less than 8 mm and no more than 12 mm, and horizontal joints should be no less than 10 mm and no more than 15 mm.

Correct filling of seams The mortar is checked by removing individual bricks of the laid row in different places (at least three times along the height of the floor).

Atforced ruptures The masonry must be done in the form of an inclined or vertical groove (a stepped break in the masonry).
When breaking masonry with a vertical groove, a mesh (reinforcement) of longitudinal rods with a diameter of no more than 6 mm, transverse rods with a diameter of no more than 3 mm with a distance of up to 1.5 m along the height of the masonry, as well as at the level of each floor, should be laid in the joints of the masonry grooves. The number of longitudinal reinforcement bars is taken at the rate of one bar for every 12 cm of wall thickness, but not less than two (for a wall thickness of 12 cm).

Height difference of the masonry being erected on adjacent sections and when laying junctions of external and internal walls should not exceed the height of the floor, and the height difference between adjacent areas of foundation laying should be 1.2 m.

Installation of fasteners in places where reinforced concrete structures adjoin masonry, they should be carried out in accordance with the design.

Construction of stone structures of the next floor is allowed only after laying the load-bearing structures of the floors of the constructed floor, anchoring the walls and sealing the seams between the floor slabs.

Atperforming work with reinforced masonry The following requirements must be met:

the thickness of the seams must exceed the sum of the diameters of the intersecting reinforcement by at least 4 mm with a seam thickness of no more than 16 mm;

when transversely reinforcing pillars and piers, meshes should be made and laid so that at least two reinforcing bars protrude 2...3 mm onto the inner surface of the pier or on both sides of the pillar;

when longitudinally reinforcing masonry, steel reinforcement bars along their length should be connected to each other by welding;

when making reinforcement joints without welding, the ends of the smooth rods must end with hooks and tied with wire with the rods overlapping by 20 diameters.

Construction of walls made of lightweight (layered) brickwork must be carried out in accordance with the working drawings and the following requirements:

all seams of the outer and inner layers of lightweight masonry walls should be carefully filled with mortar, jointing the façade seams and grouting the internal seams, with the obligatory wet plastering of the wall surfaces on the room side;

slab insulation should be laid to ensure a tight fit to the masonry;

metal connections installed in masonry must be protected from corrosion;

Loose fill insulation or lightweight infill concrete should be laid in layers, compacting each layer as the masonry is built.

Acceptance of stone structures. Acceptance of completed work during the construction of stone structures must be carried out before plastering their surfaces.

The conformity assessment of completed work (elements of masonry structures), the results of which become unavailable for control after the start of subsequent work, should be carried out on a commission basis, certifying their compliance with the project and regulatory and technical documentation. Technical supervision of the developer (customer) of construction assesses (together with the work contractor) the conformity of the work performed, structures, and signs bilateral acts confirming compliance; control over the implementation by the work contractor of the requirement that subsequent work is inadmissible before the signing of the specified acts. Representatives of the relevant state supervision bodies, designer's supervision, as well as, if necessary, independent experts may participate in these control procedures. The results of acceptance of work hidden by subsequent work, in accordance with the requirements of design and regulatory documentation, are documented in certificates of inspection of hidden work. The developer (customer) may require a re-inspection after eliminating the identified defects.

These elements include:

places where trusses, purlins, beams, floor slabs are supported on walls, pillars and pilasters and their embedding in masonry;

fixing prefabricated reinforced concrete products (eaves, balconies and other cantilever structures) in masonry;

embedded parts and their anti-corrosion protection;

reinforcement laid in stone structures;

sedimentary expansion joints, anti-seismic joints, hydro- and vapor barrier of masonry.

Atacceptance of completed work for the construction of stone structures it is necessary to check:

the correctness of the dressing of the seams, their thickness and filling, as well as the horizontality of the rows and the verticality of the corners of the masonry;

correct construction of expansion joints;

correct installation of smoke and ventilation ducts in the walls;

quality of surfaces of façade unplastered brick walls;

geometric dimensions and position of structures (deviations from the design values should not exceed those indicated in Table 2.1).

Table 2.1

Maximum deviations of sizes and positions

stone structures from design values (Fig. 2.2)

Geometric

options

Limit deviations

for structures, mm

Control

(method/type)

registration

made of brick, ceramic and

from rubble and rubble concrete

walls

pillars

foundations

walls

pillars

Structure thickness

±15

±10

±30

±20

Measuring (roulette/ruler/

work log)

Reference marks

surfaces

–10

–25

–15

Same

Width of piers

–15

–20

Opening width

Displacement of the vertical axes of window openings from the vertical

±20

End of table. 2.1

Geometric

options

Limit deviations

for structures, mm

Control

(method/type)

registration

made of brick, ceramic and

natural stones of regular shape, large blocks

from rubble and rubble concrete

walls

pillars

foundations

walls

pillars

Displacement of structure axes from alignment axes

±10 (±10)

±10

±20

±15

±10

Measuring (level/geodetic as-built diagram)

Deviations of surfaces and corners of masonry from the vertical:

one floor

for a building more than two floors high

±10 (±5)

±30 (±30)

±10

±30

±20

±30

±15

±30

Measuring (theodolite/geodetic as-built diagram)

Thickness of masonry joints:

horizontal

vertical

–2; +3

–2; +2

–2; +3

–2; +2

Measuring (ruler, tape measure/work journal)

Deviations of masonry rows from the horizontal per 10 m of wall length

±15 (±15)

±30

±20

Measuring (level/geodetic as-built diagram)

Irregularities on the vertical surface of the masonry, discovered when applying a 2 m long batten

±10

±5

±15

Technical inspection (rail, ruler/work log)

Ventilation duct cross-sectional dimensions

±5

Measuring (ruler/work journal)

Note. The dimensions of permissible deviations for structures made of vibrated brick, ceramic and stone blocks and panels are given in parentheses.

Rice. 2.2. Scheme of operational quality control of stone structures

Incoming control checks the compliance of the quality indicators of purchased (received) materials and products with the requirements of standards, technical specifications or technical certificates for them specified in the design documentation and (or) the contract.

At the same time, the presence and content of accompanying documents of the supplier (manufacturer) are checked, certifying the brand of materials, semi-finished products and products used.

If necessary, control measurements and tests of the above indicators can be performed. The results of the incoming inspection must be documented.

2.2. Method of doing the work

1. Carefully read the theoretical part of the work.

2. On the proposed site of the constructed building, carry out the necessary measurements and conduct an inspection of the quality of the brickwork:

measure the width of walls and openings using a tape measure or laser range finder;

determine the verticality of the corners of the masonry in two planes using a plumb line, level and theodolite according to the method outlined below;

determine local unevenness of the masonry surface detected when applying the rule;

measure the horizontality of the masonry rows using a level or level.

Measurementswidth of partitions, sizes of window openings Andseam thickness (vertical and horizontal) are made using a tape measure, ruler, laser range finder.

Measurements– theodolite position;a B C D E F - theodolite tube aiming points, upper and lower; δ – deviation

Before using a theodolite, the required geodetic verifications must be performed.

First, the theodolite tube is pointed at the top point of the plane or angle being examined (pointa, c, d), and then lower the pipe to the lowest point (pointb, d, f) and determine the deviation.

Measurementhorizontality of masonry rows performed using a level (Fig. 2.4). Before using it, it is necessary to perform the required geodetic checks (check the horizontal level).

Rice. 2.4. Measuring the horizontality of masonry rows:
a, b – start and end points of measurement (length of the row being tested is 10 m);δ – deviation

3 . Present the results in the form of a table. 2.2, draw a sketch, indicate instruments and measurement locations.

4. Compare the results obtained with the values allowed by SNiP 3.03.01-87, and draw a conclusion about the quality of stone work.

Table 2.2

Measurement results

Verifiable

options

Methodology

carrying out

measurements (sketch)

Acceptable

deviations, mm (according to SNiP 3.03.01-87)

Actual

deviations,

Conclusion

Thickness of masonry joints:

vertical horizontal

With a ruler in the direction transverse to the seam

Horizontality of masonry rows per 10 m length

According to Fig. 2.4

Verticality of masonry corners:

one floor

for a building two high

or more floors

According to Fig. 2.3

Width of piers

Roulette

Opening width

Roulette

Structure thickness

Roulette

Deviation of openings from the vertical

According to Fig. 2.3:

theodolite using opening marks

Control questions

How to determine horizontal and vertical rows of masonry?

What is the permissible deviation?

What is the permissible thickness of horizontal and vertical joints?

What are the requirements for lightweight masonry?

What structural elements and types of work are subject to conformity assessment with the preparation of reports for hidden work?

How to determine the correct suture ligation system?

What is a penalty and why is it performed?

What is controlled when constructing walls made of lightweight (layered) brickwork?

How and how to determine the offset of the wall reference axes?

What is controlled when accepting completed work? for the construction of stone structures?