The cause of the sinking pipe wall concrete cracking phenomenon analysis and processing method

Phenomenon: after demoulding, pipe sinking pipe wall concrete crack is serious, a concrete block falls. Reinforced concrete pipe, along the reinforced concrete skeleton layered place to fall, serious when the collapsed tube or pipe after demoulding suddenly collapsed. At the end of the curing kiln, will fall or collapse. Cause analysis: 1, the workability of concrete. When the concrete was wet, after parting wall concrete cracking due to the weight of sinking, serious when a concrete block falls. Reinforced concrete pipe along the reinforced concrete skeleton layered place to fall, serious when concrete fall across the board. When the concrete dry loose, extrusion is close-grained, not unable to bear weight of tube, easy to suddenly collapse. 2, concrete mixing unevenly, the stone is too concentrated, the extrusion speed too fast, not dense wall concrete. 3, sand, stair with bad, big stones, the needle flake stone is too much, sand ratio too hours, extrusion pressure attenuation along the pipe wall. Wall concrete seriously imperfect. 4, extruding machine malfunction, the host pump output pressure is small, extrusion pressure is not enough, not dense wall concrete. 5, steel skeleton is not vertical, positioning, deviation. Side concrete thick, demoulding after the concrete, crack, falling; Concrete reinforcement skeleton diameter is too small, the lateral partial thick, easy to crack after demoulding, morphology; Reinforced by extrusion deformation when molding, reinforced the springback after demoulding, make the surface of concrete cracking, cause cave, cave serious when easy to make the whole pipe down. 6, floor paint, curing kiln tube put instability, tilt, serious when collapsed. Shuttle buses move not smooth, collision, the history of the car just release pipe vibration. 7, static stop when maintaining time is short, a began to put too much gas, heat up too fast. Measures: 1, found the cave after demoulding, should be back to shape. 2, after arrival, curing kiln, morphology, and lesser area is not too serious, with cement, sand = 1:3:6:10 'mixed epoxy resin mortar to fill, compaction, smoothing, strengthen the maintenance. Maintenance after arrival from the kiln serious collapsing, should make processing of nonconforming product.