The pumping height and length did not adjust the mix ratio in time.
1. A serious blockage occurred in the supply process of the basement floor C40P8 of a project, and the length of the pump pipe on site exceeded 200 meters.
2. During the construction of a column wall in a project, the pipe blocking phenomenon occurred many times.
Analysis of reasons: The construction unit is issuing a production task without specifying the pumping height or the length of the pumping horizontal pipe, and the proportion of ordinary 5-31.5mm crushed stone and ordinary pumping slump is opened to cause pipe blocking and tube burst.
1) When the pumping height exceeds 20 layers or 60 meters, the particle size of 5-25mm crushed stone must be indicated, and the slump should be ≥160mm.
2) The pump trucks should be laid horizontally and vertically to minimize the number of elbows and variable pipes. If the length of the horizontal pipe exceeds 150 meters, the slump should be ≥160mm.
The change of sand fineness modulus affects the slump of concrete.
The slump is too large during the construction of a project, and the concrete is segregated.
Analysis of reasons: The river sand fineness modulus becomes larger, the specific surface area decreases, and the slump becomes larger.
Corrective measures: The river sand entering the factory should be mixed uniformly. If the detection fineness modulus changes greatly, the construction mix ratio should be adjusted in time.