The project uses C30 grade concrete, the amount of water is 175kg, the amount of cement is 461kg, the amount of sand is 512kg, the amount of stones is 1252kg, and the mix ratio is 0.38:1.1:1:2.72. In the process of pouring concrete, it is necessary to ensure that the position of the steel bars and the thickness of the protective layer are accurate, and repeat inspections to eliminate errors. For dense steel bars, stones of appropriate particle size can be used, and the maximum particle size should not exceed 1/4 of the minimum size of the cross section. It is greater than 3/4 of the net spacing of steel bars. For locations with small cross-sections, fine-stone concrete can be used for pouring; concrete should have strong workability and mix ratio. Wooden formwork should be fully moistened before filling the gap. When the pouring height exceeds 2m, collusion should be used in the process of vibrating, it is forbidden to collide with the steel bar. Vibrating rods with a smaller diameter can be used to vibrate the protective layer in densely populated areas. It is forbidden to step on the steel bars. Correction should be made in time, when demolding, the time for demoulding should be determined according to the pressure test results of the test block to avoid damage to edges and corners caused by premature demolding.
3.5 Block works
In view of the strength and quality of porous bricks in this project, factors such as pore type, sintering time, conditions, etc. should be paid attention to in the design process, and the inspection of finished bricks should be strengthened to ensure that the quality of the bricks can be put into the market after they are qualified. Before the block project officially starts, the materials should be strictly inspected when entering the site, and the factory certificate should be produced. Strictly control the strength of the mortar. First, inspect the quality of the raw materials to strictly control the mortar mix ratio to make it consistent with the construction requirements of the site. The adaptation is determined in the laboratory. When the ratio of general wall cement to sand is selected, The ratio of cement to sand in No. 100 mortar is 1:4, and the ratio of cement to sand in No. 75 mortar is 1:3. For this project, the ratio of 1:5 should be used for the masonry; then, the measuring instruments are used for inspection, storage and maintenance on the spot, mixing and feeding in two times, adding part of the sand, water and plasticized materials for the first time and mixing evenly , Add the remaining mud and sand to it for the second time and stir; finally, make and maintain the test block to ensure that the compressive strength value fully meets the acceptance standard of masonry engineering.
To sum up, the content of construction projects is very wide and the process is complicated. Once a certain process is not handled properly, it will cause various quality problems. In this regard, managers should pay more attention to the actual situation of the project, analyze the performance and causes of common quality problems, and strengthen the awareness of quality and responsibility in construction, and take diversified measures with the help of a scientific and complete quality and safety guarantee system. Carry out prevention and solution, so that the overall quality of construction projects has been comprehensively improved.
The end.BOFU plastic formwork system