再生混凝土强度和耐久性能试验

Experimental study of behavior of strength and durability of recycled aggregate concrete

为了研究再生混凝土的基本力学性能和抗冻耐久性,试验中考虑再生骨料的来源和替代率、水胶比、粉煤灰掺量和含气量等因素,对14个系列混凝土的7d和28d抗压强度、抗折强度和弹性模量等进行了试验,对其中8个系列的混凝土进行了快速冻融试验,采用共振法测试了其相对动弹性模量和重量损失率。结果表明,再生骨料的饱和面干密度比天然骨料的要小一些,而其吸水性比天然骨料的要大;再生骨料的替代率和来源对再生混凝土强度影响基本在10%范围之内;采取外掺粉煤灰和引气剂所配置再生混凝土,其抗冻性会有很大程度的提高,可以满足寒冷区域环境下使用;再生混凝土的弹性模量比普通混凝土的要低一些,这些对变形和施加应力等产生的影响,应进一步研究和分析。

To study freeze-thaw durability and the basic mechanics function of the recycled aggregate concrete,experiment to consider the source and replacement ratio of the recycled aggregate, water-cement ratio, the fly ash content, air content etc.were carried on, including 14 series of 7d and 28 d compressed strength, bending strength and the modulus of elasity etc, from which 8 series carried on the fast freezing and thawing test, adopting the resonance method to test it relative dynamic modulus of elasticity and measure it weight loss.Experimental results express that the density of recycled aggregate trader saturated dry condition is smaller than the natural aggregate, but it absorbs more water compared with natuml aggregate;The recycled aggregate will have the influence to the recycled concrete strength in lieu of the rate and sources, but it affects the scope not more than 10% ;Adding the fly ash and air entrainment to recycled concrete, its anti-freeze ability will be much enhanced, can satisfy the environment of the cold district usage.The modulus of elasticity of recycled aggregate concrete is lower, these produce the influence towards deformation and exerting stress, which should be further researched and analyzed.