不同掺量石蜡相变混凝土单轴抗压性能试验研究

以石蜡为相变材料掺入到混凝土中,以期通过相变材料石蜡的相变过程吸放混凝土中水泥水化产生的热量,使混凝土内外温差减小,从而自动实现控温的效果。相变混凝土为解决大体积混凝土温度裂缝提供了新的思路,但石蜡掺量对混凝土力学性能的影响需要进行研究。制备石蜡相变混凝土时将石蜡以体积代砂法掺入,分别按照砂子体积的10%、20%、30%、40%、50%、60%、70%、80%的含量掺入混凝土中,分别制成100mm×100mm×100mm和150mm×150mm×300mm的石蜡相变混凝土试块,采用微机控制电液伺服万能试验机分别开展立方体抗压强度试验和轴心抗压强度试验研究,分析不同石蜡掺量对混凝土强度的影响以及破坏形态。实验结果表明:相变材料石蜡的掺入会导致混凝土抗压强度降低,随着石蜡掺量的增加,混凝土的单轴抗压强度会出现明显地持续降低;随着石蜡掺量的增加,混凝土能承担的最大荷载逐渐减小,且对应的位移逐渐减小;随着石蜡掺量的增加,混凝土表面无大面积脱落现象,整体性较好。

Paraffin is used as phase change material to mix into concrete in order to absorb the heat generated by hydration heat of cement in concrete through the phase change process of phase change material paraffin, so that the temperature difference between inside and outside of concrete can be reduced, and the effect of temperature control can be realized automatically. Phase change concrete provides a new way to solve the temperature cracks of mass concrete, but the influence of paraffin content on the mechanical properties of concrete needs to be studied. When preparing paraffin phase change concrete, the paraffin wax is added into the concrete by volume instead of sand. According to the content of 10%、20%、30%、40%、50%、60%、70% and80% of the sand volume, the paraffin phase change concrete blocks of 100 mm×100 mm×100 mm and 150 mm× 150 mmx×300 mmare made respectively. The hydraulic servo universal testing machine controlled by a computer is used. Cubic compressive strength test and axial compressive strength test were carried out to analyze the influence of different paraffin content on concrete strength and failure mode. The experimental results show that the compressive strength of concrete decreases with the increase of paraffin content, and the uniaxial compressive strength of concrete decreases continuously with the increase of paraffin content. With the increase of paraffin content, the maximum load that concrete can bear decreases gradually, and the corresponding displacement decreases gradually. With the increase of paraffin content, there is no large area falling off on the surface of concrete, and the integrity is good.