合成纤维混凝土板早期抗收缩裂缝的试验研究

混凝土的早期收缩裂缝虽然对结构的承载能力不会产生太大的影响,但会影响结构的使用寿命、缩短结构维修周期.通过合成纤维混凝土的20个平板试件的试验,着重研究各品牌的聚丙烯纤维的掺量与防裂效果之间的关系,并给出合成纤维用于混凝土防裂的合理掺量;得到了不同长径比、掺量情况下纤维防裂效果曲线,揭示了纤维长度和租集料粒径在基体混凝土中防裂作用的机理,给出不同长度纤维的使用场合;建立了不同弹性模量、不同掺量情况下纤维防裂效果曲线,给出了应选用高弹性模量纤维的建议.

An experiment research on early cracking properties of synthetic fiber reinforced concrete

The shrinkage crack of early-age concrete has always existed ever since the birth of concrete.Although it doesn't affect the loading-carrying capacity of the structure greatly,it affects the building's service life and reduces the maintenance cycle of the structure. In this paper,through the flat experiments of different type synthetic fiber reinforced concrete,the crack-resistant capabilities of the concrete with different volume ratio of fibers are studied.The reasonable volume fraction is recommended.The curves of the effects of the volume ratio,the rate of length and diameter on cracking of concrete are drawn.The anti-cracking mechanism of the length of the fiber,the diameter of coarse aggregate is revealed.The usage occasion of the fiber of different length is recommended.The curves of the effects of the modulus,volume fraction on cracking of concrete are drawn.We'd better use the fiber of higher modulus.