考虑荷载耦合的再生混凝土路面砖抗碳化试验研究

Experimental Research into Anti-Carbonization of Recycled Concrete Pavement Brick Considering the Coupling Load

提高再生混凝土的抗碳化性能是改善其耐久性的一个重要措施。采用正交试验,探讨水胶比、再生粗骨料取代率以及拉应力水平等因素对抗碳化性能的影响规律,并确定最优配合比,制作再生混凝土路面砖。结果表明:随着再生粗骨料取代率的增大,再生混凝土28天抗压强度明显降低,当取代率为60%时,抗碳化性能较好;随着拉应力水平增大,碳化抗力降低;再生混凝土的碳化深度与时间的平方根呈线性关系,抗碳化性能劣于天然混凝土。所制作的路面砖抗压强度和抗折强度良好,抗碳化性能良好。

The improvement of anti-carbonization performance of recycled concrete is an important measure to perfect its durability. Based on an orthogonal experiment,this paper probes into the influence of such factors as water-cement ratio,recycled coarse aggregate replacement rate and tensile stress level on the property of carbonation resistance of recycled concrete,and determines the optimum mix proportion to make recycled concrete pavement brick. The result shows that with the increase of recycled coarse aggregate replacement rate,28 day's compressive strength of recycled concrete obviously decreases,and the anti-carbonation performance of concrete is better with the replacement rate of 60%; the carbonation resistance of recycled concrete lowers with the increase of tensile stress; the carbonation depth of recycled concrete has a positive correlation between the carbonization and the square root of time,and its anti-carbonization performance is worse than natural concrete; the mechanical properties of the produced pavement brick such as compressive strength and bending strength and the anti carbonization performance are both good.