单轴压缩下泡沫混凝土的强度特性研究

以水泥、粉煤灰、矿渣为胶凝材料,水胶比0.43,按照质量比16∶3∶1制备出不同气泡含量泡沫混凝土。通过室内试验,对不同气泡率下(0%~74.23%)泡沫混凝土进行单轴压缩破坏试验,得到其不同龄期下(7 d、14 d、28 d)的抗压强度和破坏形态,建立了强度与龄期和气泡率之间的关系。结果表明:泡沫混凝土在单轴压缩下经过密实、弹性、屈服、破坏四个阶段,其抗压强度随泡沫含量增大而减小,在一定范围内随着龄期增大而增大;泡沫混凝土抗压强度与气泡率之间成指数关系,且一致性良好;对于气泡含量高的试样,其破坏形态表现出低强度脆性破坏特征,在中部形成较宽裂缝,而对于气泡含量低的试样,其破坏形态与普通混凝土基本一致。

Strength Characteristics of Foam Concrete Under Uniaxial Compression

Foam concrete with different content of foam was prepared with cement,fly ash and blast furnace slag as binding materials and according to the mass ratio 16:3:1,water-binder ratio 0.43.Through laboratory tests the uniaxial compression tests for foam concrete under different rate of foam (0％ ～74.23％) at different curing age (7 d,14 d,28 d)were conducted to study compression strength and failure mode,the stress-strain curve of foam concrete and the relationships between compressive strength and curing age,rate of foam were analyzed.The research results indicate that there are four stages in foam concrete to uniaxial compression process,namely densification stage,elastic stage,yield stage and failure stage;the higher content of foam,the lower the compressive in a certain range increases with curing age.The relationships between compressive strength and the rate of foam were studied by fitting and show an exponential relationship between each other.Also the fitting curve has a good consistency with test data.For samples with high content of foam,the failure pattern shows low strength and brittle failure characteristics,and forming a wide crack in the middle of sample,while the sample with low content of foam,the failure pattern of foam concrete is similar to ordinary concrete.