机制砂成分对隧道混凝土抗硫酸盐侵蚀性能的影响

Effect of the Compositions of Machine-made Sand on the Sulfate Resistance of the Tunnel Concrete

基于机制砂混凝土在隧道工程服役过程中出现的侵蚀破坏现象,采用相同的原材料、配合比进行混凝土加速侵蚀试验,研究了机制砂成分对隧道混凝土抗硫酸盐侵蚀性能的影响。结果表明,含有石膏矿物相且石粉含量较多的机制砂制备出的砂浆试件,在低温环境下发生了硫酸盐侵蚀破坏。因此,在低温环境下使用机制砂作为隧道混凝土细骨料时,必须检验并控制其成分,防止其对混凝土的耐久性带来不利影响。

Based on the erosion and damage phenomenon of machine-made sand concrete in the service process of tunnel engineering,the accelerated erosion test of concrete was carried out with the same raw materials and mix proportion,and the influence of the compositions of machine-made sand on the sulfate corrosion resistance of tunnel concrete was studied.The results show that the mortar specimens prepared from machine-made sand containing gypsum mineral phase and high content of stone powder suffer sulfate erosion damage at low ambient temperature.Therefore,when machine-made sand is used as tunnel concrete fine aggregate in a low temperature environment,its composition must be inspected and controlled to prevent it from adversely affecting the durability of concrete.