(1) The base of the steel cage and drilling should correspond, and the positioning should be accurate. If the rebar cage is not placed at the bottom of the hole, pay special attention to the strength and robustness of the hoop and hook. When the steel cage is hoisted, adhere to the axis straight, the azimuth center, stop the bump hole wall, prevent the attack collapse hole. The catheter should be installed immediately after the steel cage is placed in place.
(2) Before filling the first batch of concrete, first manufacture 0.1~0.3m3 cement mortar into the sliding valve above the catheter and funnel, and then put into concrete, confessed to the initial irrigation needed are adequate, you can cut the wire, by virtue concrete components to clean the water inside the catheter, so that the sliding valve left at the bottom of the hole, into the first batch of concrete.
(3) Note that the first batch of concrete quantity is necessary to be satisfied with the depth of the catheter should not be less than 1.5m, so the funnel and storage hopper and funnel and conveyor pump concrete storage quantity to meet. If the buried depth of the channel is lacking, the concrete can not sink the bottom of the catheter after irrigation, which will cause the muddy water to enter from the bottom of the catheter. If this catheter into the water scene should be immediately proposed, the concrete mixture scattered at the bottom of the hole with an air suction machine or grab machine to clear out, and then perfusion from the beginning of the catheter.
(4) After the first batch of concrete perfusion is normal, it is necessary to carry out continuously and without interruption. Otherwise, the concrete injected first reaches the initial condensation, and the concrete poured into the deterrent flows out of the catheter, which constitutes a broken pile. If necessary, a retarder can be added to the first batch of concrete to delay the initial condensation time of the concrete. In the perfusion process, the hammer should often be used to explore the rising height of the concrete surface, and when the progress is made, the catheter is disassembled, and the reasonable buried depth of the catheter is adhered to. At this time to pay attention to, concrete irrigation to the orifice no longer return to the mud can be slightly upward lift the catheter, and if you want to improve the catheter 0.5m~1.0m above the ability to fill the concrete should be removed some catheters. Be aware that the query hole is not returned to the mud. When the concrete is near the steel cage, it is advisable to use the catheter to bury it deeper. To pay attention to the precise control of the catheter buried depth, easy to make the catheter and concrete between the friction resistance is too large, so that the catheter can not be pulled out to form trouble. And in the process of extubation should be slowly raised, such as too easy to make the catheter pull off. Therefore, the depth of buried pipe should generally be controlled at 2 to 6m, or the use of adhesion shock device, so that the concrete around the catheter does not prematurely initial condensation, together should pay attention to the perfusion speed.
(5) In order to ensure the quality of the pile top, in the pile top planning elevation above should be added to the height of the 0.5~0.8m, to pile top concrete strength to reach the planning strength of 70%, it will be chiseled. In the perfusion fast to the end, such as the occurrence of concrete top rise difficult, can dilute the mud in the Konnega, will be some stacked soil pulled out, so that the perfusion work smoothly. When pulling out the final long catheter, the extubation speed is slow to prevent the mud piled up at the top of the pile from squeezing into the catheter to form the mud heart.
(6) Other precautions: after mixing concrete, Should be perfusion within 1.5h as far as possible; clear hole should be thorough, if the hole is not completely will constitute the concrete clamp mud, in the perfusion process, when the catheter concrete is dissatisfied with the budding air, the subsequent concrete should be slowly flowing through the chute into the funnel and catheter, not the concrete bucket from the top into the tube, to prevent the formation of high-pressure And make the catheter leak.
Previous: No Information