掺新型膨胀材料混凝土渡槽早期抗裂性研究

Early cracking resistance of large concrete aqueduct with movel expansive agent

大型混凝土渡槽易发生收缩开裂，严重影响渡槽的耐久性。掺新型膨胀材料可补偿混凝土收缩，降低和抑制混凝土渡槽开裂。采用平板法和圆环法对混凝土渡槽早期抗裂性能进行研究，探讨新型膨胀材料对混凝土渡槽早期塑性开裂性能的影响。研究结果表明：掺4％-8％的膨胀材料可有效补偿和降低混凝土收缩，降低和抑制裂缝的产生和扩展，掺8％的抗裂性能最佳。

Cracks occur easily in large concrete aqueducts, which affect the durability of the aqueducts. A novel expansive agent was used to compensate the autogenous deformation, and to reduce the aqueduct cracks caused by concrete shrinkage.To study the influence of the new expansive materials on the early - age cracking behaviors of concrete aqueduct, the cracking behaviors of concrete aqueduct was analyzed using the modified flat - type specimen and ring test. The results show that the optimal content of expansive materials is 4% to 8%of cementing material.Under the conditions of the optimal content,the early age cracking resistance of concrete is higher than other content,the crack resistance performance is best when the content is 8%.