砾石混凝土抗冻性能研究

Study on Frost Resistance of Gravel Concrete

黑龙江省河流分布较广,河流水系沿线有较为丰富的砾石资源,可作为粗骨料充分运用到水泥混凝土路面中,以达到减少工程成本的目的,由于黑龙江省特殊的地理气候环境,冻融循环是影响混凝土路面耐久性的重要因素之一,在设计路面时必须考虑砾石混凝土路面的抗冻性能。本文以黑龙江乌斯浑河流域平山段砾石为原材,通过混凝土快速冻融循环机对砾石混凝土抗冻性能进行研究。研究结果表明:随着冻融循环次数的增加,砾石混凝土动弹模量降低,质量损失率增加,混凝土的抗冻性能减低;级配在5~26.5mm范围内的砾石混凝土抗冻性能最佳;在冻融循环达到200次后,掺引气剂砾石混凝土的抗冻性能明显好于未掺引气剂。研究结果为黑龙江省县乡村公路的建设提供理论参考,对工程实际具有一定的经济意义。

The rivers in Heilongjiang province are widely distributed,and there are abundant gravel resources along the river system,which can be used as course aggregate in cement concrete pavement,in order to reduce the cost of the project.Because of the special geographical and climatic environment in Heilongjiang Province,freeze-thaw cycle is one of the important factors that affect the durability of concrete pavement.The design of pavement must take into account the frost resistance of gravel concrete pavement.Using Pingshan Hunhe River gravel in Heilongjiang as raw material,the frost resistance of gravel concrete was studied by the rapid freezing and thawing machine.Results show that：with the increase of freeze-thaw cycles,the modulus of elasticity of gravel concrete decreases,mass loss rate increases and the frost resistance of concrete decreases.The frost resistance of gravel concrete in 5-26 5 mm range is the best.After freezing and thawing cycles reached 200 times,the frost resistance of gravel concrete with air entraining agent is better than that without air entraining agent.The results provide theoretical reference for the construction of rural roads in Heilongjiang province,which has certain economic significance to engineering practice.