Reinforced concrete produce a boutique with beautiful appearance. In addition to the excellent quality of the concrete pipe mould, the most important and most difficult to master is the refined process requirements in the construction of concrete.To ensure culvert quality, concrete raw materials, process requirements are as follows:
1.The strength of not less than 32.5 Rapid harding portland cement or ordinary Portland cement should be choose.When there is a special need, high-strength cement can be choose or admixture can be add.
2.The purchase, processing, production of reinforced cage skeleton are in accordance with the design drawings. It require the precision size, solid binding, no wrong place, less place, leakage phenomenon.
3.Coarse aggregate should be used in dense, hard, high strength, good durability of gravel or pebbles.Particles should be selected according to the concrete structure and construction method.Its particle size shall not exceed 1/4 of the minimum size of the structure, and 3/4 of the minimum clearance of the reinforcement. Above two layers of dense steel structure is not more than 1/2 of the minimum clearance.
4.To meet the requirements and select the coarse sand that fineness modulus of 2.6 to 3.7, and the concrete quality and engineering workability requirements can be meet at the same time.
5.Mix Proportion:According to the concrete mix design, follow the following principles: ① the concrete strength and durability requirements that conforms to the specification should be meet; ② Sand ratio ofsand aggregate select the upper limit of the recommended value as much as possible, promoting concrete to achieve uniform density and fully improve the workability of concrete mix; ③ Water consumption take the lower limit and try hard to use concrete to speed up the demoulding progress.
6.Concrete mix is the raw materials of culvert forming. For control process of concrete appearance quality , one of the most important part is the concrete slump control. To achieve the color sense unifomity of the concrete appearance after the concrete form stripping, the concrete slump uniformity is also required. In production practice, our experience is that concrete slump either "big" (slump 20cm up and down), which more cement content in mixture and better concrete outlook brightness but the disadvantage is that the oversize slump will affect the time into tube. Or "small" (slump 10cm below), which less water content in mixture and easy to overcome water bubbles in concrete. But it with small slump often has less shiny and easy to cause the local stripping when round culvert molded is demoulding, which is not conducive to the appearance and quality of round culvert.