低热混凝土早期抗裂性能试验研究

Testing study on early cracking resistance of low heat concrete

低热混凝土具有常规混凝土所不具备的早期低热、后期强度发展快等优点。除了经济因素外,目前制约着低热混凝土广泛使用的主要因素是其早龄期的低强度,但是低强度并不一定意味着低的抗裂性能。水工大体积混凝土开裂的主要原因是温度应力,其产生与温度梯度和混凝土的自身性质均有关。温度断裂试验是一个可以综合考虑混凝土自身性质和外界温度条件的试验手段,笔者以该试验对比了低热混凝土和中热混凝土抵抗温度断裂的能力。

Lowheat concrete has many advantages like lowtemperature rise in the early age and fast strength development in the later age which conventional concrete does not have. At present,except for economic factors,the main factor restricting the widespread use of lowheat concrete is its lowstrength in the early age,but lowstrength does not necessarily mean lowcrack resistance. Another important index to judge whether it is of ability to work or fails is cracking characteristics. The main reason of hydraulic mass concrete cracking is the temperature stress,and the temperature stressdepends on the temperature gradient and the properties of concrete itself. The temperature fracture test is a comprehensive test which could takeboth concrete properties and the outside temperature conditions into consideration,and the author took the test to searchthe resistance of temperature fracturecomparing the two kind of concrete.