What are the specific treatment methods for constr

2022-07-22
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Construction joint refers to the joint formed between the first and second poured concrete due to the design requirements or construction needs of segmental pouring during the concrete pouring process. There are many factors that affect the quality of construction joints, and there are many treatment methods of construction joints. The following editor will briefly introduce the treatment methods of construction joints

construction joint refers to the joint formed between the first and second poured concrete due to the design requirements or the construction needs of segmental pouring during the concrete pouring process. There are many factors that affect the quality of construction joints, and there are many treatment methods of construction joints. The following editor will briefly introduce the treatment methods of construction joints

· Various factors affecting the quality of construction joints

(I) reasons for engineering design drawings and construction process, such as the retention of construction joints in the area of possible stress concentration; The structural reinforcement is too much or too little or deviates from the shear zone

(II) reasons for concrete materials: the sand and stone content of post cast concrete is too large; The aggregate particle grading is uneven, and the cement variety and dosage are unreasonable; Concrete mineral admixtures and admixtures are improperly selected or not added as required, increasing the shrinkage of concrete; Incorrect vibration method during construction; When pouring concrete at high altitude, the wind speed is too high, the hot sun is exposed, and the concrete shrinkage value increases, which will cause cracks in the construction joints

(III) reasons for on-site construction: incorrect vibration method during construction; The loose concrete and stones at the construction joint are not removed in place, the dust is not cleaned up, and the construction joint is not watered before pouring the second concrete again; When the weather is hot, the concrete loses too much water too quickly without taking protective measures; Before pouring concrete, sundries and garbage falling into the joint are not checked and cleaned in time, resulting in the formation of interlayer between the new and old concrete; The cutting method is improper, and the aggregate is concentrated at the bottom or one of the construction joints; The expansion waterstop or waterstop steel plate is not placed or correctly placed in the construction joint; Micro expansive concrete is not used, so that the joints cannot be closely connected

(IV) reasons for maintenance and environment at the construction site: protective measures such as curing, covering and wind protection shall be taken in time for newly poured concrete to prevent rapid water loss of concrete and early removal of on-site formwork

(V) the cracks caused by construction joints due to use mainly include: uneven settlement of structures; The service load exceeds the design specification; Rough decoration is adopted, and load-bearing walls or walls, beams, columns, etc. are demolished at will; The impact of the surrounding environment, acid, alkali, salt and other erosion of the structure, causing accelerated aging and cracks of the construction joints

· Treatment method of construction joint

before continuing to pour concrete on the hardened concrete surface (the concrete strength is required to reach 1.2MPa), the garbage, loose sand and gravel and weak concrete layer on the surface of the cement film should be cleaned up At the same time, the surface shall also be roughened. Wash it with water and fully wet it. Generally, the wetting time should not be less than 24h. Remain in coagulation

the relevant information about the treatment method of construction joints is introduced here. I hope this article is helpful to you. If there is anything else you don't understand, you can follow us and we will answer it for you as soon as possible

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