Cold joints occur in the pouring process of reinforced concrete structures. Cold joints will bring great hidden dangers to reinforced concrete structures, affecting the gripping force of concrete on steel bars, the integrity of reinforced concrete structures, and the protective effect of concrete on steel bars. Water may rust steel bars through cold joints, affecting the self-waterproof and service life of the structure.
The setting of longitudinal and transverse joints, 1/3 span of structural members (prestressed members should not be considered). The horizontal joint is generally set up: the top surface of the foundation, the upper and lower floors. In short, the construction joint is set in the part of the force is small. Cold joint refers to the phenomenon that the strength of both sides of the concrete pouring time is not improved at the same time. Cold joint is the weak zone of the structure should be reduced as far as possible, so the concrete pouring must not exceed the continuous break time of the initial setting time.
Pouring: civil engineering refers to the pouring of concrete and other materials into the mold to make a predetermined shape. When concrete is poured, the free height of concrete shall not exceed (3) m.
When large volume concrete is poured, it can adopt comprehensive stratification, subsection stratification and inclined plane stratification. For concrete poured in winter, before curing from positive temperature to negative temperature, the compressive strength of concrete should not be less than 40% of the design strength, and for concrete below c10, it should not be less than 5mpa. That is to say, in the case of strength does not meet the requirements should first take some insulation measures, until the strength meets the requirements.