泄水建筑物抗冲磨混凝土降粘抗裂性能研究

Research on Viscosity Reduction and Crack Resistance of Abrasion Resistant Concrete for Outlet Structure

为改善抗冲磨混凝土的施工性和抗裂性、延长泄水建筑物衬砌混凝土的使用寿命,选用了一种新型的抗裂降粘剂,并以掺硅灰、纤维、HF剂的混凝土为比较对象,对四种混凝土的工作性能、力学性能、抗冲磨性能及抗裂性进行对比试验。结果表明,掺加抗裂降粘剂可大幅降低抗冲磨混凝土的塑性粘度,改善混凝土施工性能;掺硅灰+抗裂降粘剂的混凝土抗压强度和抗拉强度整体上优于其余混凝土,且抗冲磨强度比HF混凝土提高40%;就抗开裂能力而言,硅灰+纤维混凝土>硅灰+抗裂降粘剂混凝土>HF混凝土。因此,抗裂降粘剂能有效降低抗冲磨混凝土的粘度、提升力学性能和抗冲磨强度,降低早期开裂风险。

In order to improve the workability and crack resistance of abrasion resistant concrete,and prolong the service life of lining concrete of spillway building,a new type of anti-crack viscosity reducer is selected.Taking the concrete mixed with silica fume,fiber and HF agent as the comparison object,the working performance,mechanical properties,abrasion resistance and crack resistance of four kinds of concrete are compared and analyzed.The results show that the plastic viscosity of abrasion-resistant concrete can be greatly reduced and the construction performance of concrete can be improved by adding anti-crack and viscosity reducer.On the whole,the compressive strength and tensile strength of concrete mixed with silica fume and anti-crack and viscosity reducer are better than those of other concrete,and the abrasion resistance is 40%higher than that of HF concrete.As far as cracking resistance is concerned,silica fume+fiber concrete>silica fume+anti-cracking viscosity reducer concrete>HF concrete.Therefore,the anti-cracking and viscosity reducer can effectively reduce the viscosity of abrasion-resistant concrete,improve the mechanical properties and abrasion-resistant strength,and reduce the risk of early cracking.