Tuesday, November 1, 2016

Ceramsite concrete construction technology of cushion

1 scope
This technology is applicable for industrial and civil construction ground concrete bedding.
2 construction preparation
2.1 materials and equipment
2.1.1 ceramic
2.1.1.1 shale ceramsite: size 5~30mm, loose bulk density is 500~700kg/M3, 3.5%~5% water absorption (dry 30mm), unripened flap should be less than 10%~15%, the particles of powder and particle size is less than 5mm should be less than 5%.
2.1.1.2 expanded clay grains: grain size 5~30mm, loose bulk density is 580~680kg/M3, 8.3%~10% water absorption (dry 1h), content of powder and particle size is less than 5mm should be less than 5%.
2.1.1.3 the flyash: size 5~15mm, the density is 630~700kg/M3, 16%~17% water absorption (dry 1h), particle size is less than 5mm or greater than 15mm content shall not be greater than 5%. And shall not be mixed or inclusions of clay blocks.
2.1.2 sand: sand or coarse sand, clay not greater than 5% when the concrete strength C10~C30.
2.1.3 cement: General, No. 325, No. 425 Portland slag cement or Portland cement.
2.1.4 admixtures: content must be determined by experiments, and according to the technical regulations.
2.1.5 major equipment:-compulsory concrete mixer or from falling concrete mixers, scales and narrow trolleys, admixtures, diluting vessels, vibrating Board, flat spade, clappers and iron drum, a small hammer, chisel and wire brush, hair brush, small half barrels, buckets, rubber pipes, wooden trowel, a smaller, 2~3M wooden bars, 5mm and 30mm aperture sieve.
2.2 operating conditions:
2.2.1 quality of structure engineering has completed the acceptance procedure, door frame is installed, +50cm level elevations have elastic around the walls.
2.2.2 through floor heating and plumbing pipes have been installed, it tube hole has fine stone concrete pouring and packing density. Laying on the floor of the electric line through the hidden procedures.
2.2.3 concrete mixture ratio determined by the laboratory.
2.2.4 If is done on the prefabricated reinforced concrete slab mat, seams must be not less than the fine stone concrete C20 dense.
2.2.5 winter indoor temperature should be maintained at + 5 ° c or more.
3 operational processes
3.1 process:
Base treatment elevation bomb ceramic sieve, water level control line boring mix

Laying concrete conservation
3.1.1 base treatment: before pouring concrete pad will be processed concrete slab base, loose at the grass-roots bonded concrete, scrape mortar with a cold chisel, use wire brush away the cement slurry, and then use a broom to sweep.
3.1.2 bomb find elevation level control line: according to the level of +50cm on the wall elevations, measure down cushion height, there are conditions to play around on the wall.
If the room is large, 2m insulation around leveling fine stone concrete Pier. There are slope requirements of the ground, according to the design requirements of the slope to find out after the highest and lowest points, draw a small line and then put the gradient piers, so as to control the cushion surface elevation.
3.1.3 ceramic sieve, water tightness: in order to clear the debris and fine powder in a ceramic, ceramic entry twice after screening. First time with a big aperture sieve (sieve pore is 30mm), the second time too small aperture sieve (sieve 5mm), keeping the content of 5mm size in less than 5% requests, placing pads on ceramic layer evenly watered ceramsite bored, water tightness shall be not less than 5d.
3.1.4 mix: first the aggregates, cement, water and admixtures are measured by weight. Aggregate measure of deviation should be allowed is less than ± 3%, cement, water and admixtures measurement tolerances shall be less than ± 2%. Because ceramic water tightness in advance, so according to sampling aggregate moisture before mixing, adjust the mixing ratio of water consumption.
Using down mixer feeding order is: first 1/2 of water, then add the coarse and fine aggregates and cement, mixing about Lmin, then add the remaining water and continue stirring at least 2min.
Using forced mixer feeding order is: fine aggregates, cement and coarse aggregate, mixing about Lmin, add water stir not less than 2min.
Mixing time is slightly longer than the ordinary concrete, about 3min.
3.1.5 the laying, vibrating or rolling: pouring concrete pad thickness must not be less than 60mm, strength shall not be less than C10.
3.1.5.1 cleaned by spraying water on the grass-roots moist.
3.1.5.2 painted cement bonding of the water/cement ratio for 0.4~0.5.
3.1.5.3 Pu has been mixing good concrete, concrete pavers with a shovel at the grass-roots level, with leveling Pier and paved the way for standard grey, 3mm higher than the level, and then use the vibrating Board of compacting screed. If thickness is thin, with Pu with a spade and a special wooden clappers make dense, and then the big bumper level, use wood trowel rubbing or rolling iron reinforced, and all operations to finish in 2H.
Pouring pottery grain concrete pad layer Shi as not left or less left construction sewing, as must left construction sewing Shi, application wood party or wood block good broken Cha at, construction sewing best left in door and aisle Zhijian, or left in has real wall of axis middle, received Cha Shi should in construction sewing at brushing water mud (W/C for 0.4~0.5) combined layer, again continues to pouring. After pouring water conservation should be carried out. Strength of 1.2MPa before the next process operations.
3.1.6 when winter construction, spraying water on the aggregate shall be subjected to freezing, there should be sufficient insulation cover. Indoor temperature to + 5 degrees or more.
4 quality criteria
4.1 project:
4.1.1 concrete pad used, cement, ceramic, such as sand, must comply with the design requirements and specification for construction and acceptance of the rules.
4.1.2 concrete bedding materials, strength, density and so on must meet the requirements of specification for design and construction.
4.1.3 concrete pad and the grassroots need to bond, without hollowing and loosely, cracks and other defects on the surface.
4.2 allowable deviation, as shown in table 7-3.
5 finished product protection
5.1 cushion in the course of construction shall not impact frames, pipe and completed the foundation wall repair surface.
5.2 the construction end of the cushion should be pay attention to conservation at room temperature behind the 3D surface construction.
5.3 cushion after pouring out to meet the conservation time, continued construction of surface layer. If protection should cover the cushion in the construction, avoid mixing mortar on the cushion, store, paint and other items to prevent pollution of cushion, affect the bond strength of surface layer and layer and causes surface layer hollowing.
Ceramsite concrete cushion tolerance table 7-3
Serial number item tolerance (mm) test method
10 2m m on foot and 1 surface flatness wedge feeler Gage check
± 10 2 elevation level and standard of inspection
3 slope of 2/1000, and not more than 30 adjustable triangle check
4 thickness although not more than 1/10 feet in thickness check

6 quality problems to be noticed
6.1 layer hollowing cracking: ceramic water tightness is not through, paving and cement bonding adhesion factors such as bad or grass-roots cleanup does not clean, can create hollow crack.
6.2 low intensity: mostly inaccurate mix, mixing short mix is not uniform, the construction operation takes too long to process, rolling or untrue (especially on the wall side), the use of outdated cement and other reasons, are all factors contributing to the low strength of ceramisite concrete cushion. Construction should be master mix, strictly control the amount of water and mixing time, strengthened cushion process of inspection work, paving, tamping, compacting, rolling, and more serious action should be.
6.3 surface evenness and level does not meet the requirements: main is laid without horizontal control or on the wall is not flat elevations on the elastic cushion, another area of the room should be leveling Pier, easy to control when laying concrete flatness.
7 quality records
This standard shall meet the following quality records:
7.1 cement factory certificate.
7.2 ceramic factory certificate.
7.3 ground waterproofing requirements, waterproof material factory certification and testing records, and inspection records.

Table 7.4 cushion section for quality inspection and assessment.

No comments:

Post a Comment