力能波纹涵管 镀锌螺纹管

beam form a unified whole. The main reasons for this quality defect are: 1. The improper selection of cement slurry and additive resulted in a large ratio of cement ash. 2. When the cement mud is prepared, the fluidity and water rate do not meet the requirements, so that some of the bellows are occupied by the water produced, and the water is absorbed or evaporated, resulting in voids. 3. The construction staff's grouting operation is not correct, the grouting speed is too fast or the grouting pressure is low. When the grouting is not waiting for the grouting hole to emerge, the grouting will stop. 4. During grouting, due to improper grouting or mechanical failure, the grouting was suspended, but the corrugated pipe behind the front grouting was not cleaned in time. As a result, when grouting again, it could not proceed normally due to blockage, forming an internal hole.