Research On Formation Mechanics And Control Of Early Age Cracking Induced By Shrinkage Of Concrete

The crack is the primary factor which reduces the durability of the concrete. At present, along with the high strength concrete and the high performance concrete's promoted application vigorously, the crack of concrete is getting more and more serious. Therefore it receives the high attention in the engineering. The early age cracking of concrete at the hardened stage is a universal question. These real questions demand us study on the formation mechanics, change, development and control measures of the early age cracking deeply.The early age cracking of concrete is comprised by the shrinkage caused by the change of moisture and temperature. This paper studies the early age cracking induced by shrinkage which is caused by moisture of concrete, including the drying shrinkage and the autogenous shrinkage. The early age cracking of concrete's engender, development and movement are really complicated. To prevent this crack is more difficult than to prevent load's crack. But concrete's crack can be controlled. Some reasonable measures should be adopted which can bring down the crack.This paper is focus on the formation mechanics of the early age cracking of concrete. The change of moisture is the main factor which causes the drying shrinkage and the autogenous shrinkage. Based on the theoretical research, we can establish the moisture field and the shrinkage stress field. We also can deduce the stress value in the concrete at any time. By using the finite element analysis software ANSYS, the moisture field and shrinkage stress field of a concrete slab are imitated. Using this method, the moisture diffusion valu and the distribution and development valu of stress in concrete can be obtained. Finally, we put forward some effective measures which can control the early age cracking of concrete.