大海子水库放水涵洞抗侵蚀混凝土试验

Erosion resisting concrete test for water release culvert of Dahaizi Reservoir

针对大海子水库放水涵洞工程地下水中含有约600 mg/L的硫酸盐,采用抗硫水泥和粉煤灰来配制混凝土进行试验,结果:粉煤灰的掺量对抗硫水泥混凝土拌合物流动性和力学性能的影响较大,当粉煤灰掺量为30%时,混凝土28 d的抗压强度、抗渗等级和抗冻等级仍满足C20、W6和F200的要求;抗硫酸盐水泥的抗侵蚀性能有限,并随着侵蚀延长而不断降低,在侵蚀24个月后侵蚀系数已低于0.85;粉煤灰对混凝土的抗侵蚀性能有改善作用,当掺量为20%和30%时,24个月的侵蚀系数均在1.0以上。

In view of the sulfate content of 600mg/L in underground water, mix proportion test was conducted with sulfate resisting cement and fly ash for the water release culvert of Dahaizi Reservoir. The results of test show that mix quantity of fly ash renders significant influence on the fluidity and mechanical properties of concrete. When the proportion of fly ash is 30%, the compressive strength, seepage and frost resisting properties of 28d-concrete con- form to requirements for C20, W6 and F200 respectively. The erosion resisting property of sulfate resisting cement is limited and reduces with time. The erosion factor is less than 0.85 after 24 months. Fly ash is capable of improv- ing the erosion resistance of concrete. The erosion factor after 24 months is more than 1.0 with the mix proportion of fly ash at 20% or 30%.