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对掺与未掺引气剂的混凝土进行了冻融破坏,通过吸水试验和中子辐射试验,研究了冻融损伤对掺与未掺引气剂混凝土吸水特性的影响.结果表明,中子成像技术能够实现对非透明性混凝土材料吸水演进过程的可视化观测和定量分析.未掺引气剂的混凝土其抗冻性较差,在10次冻融循环后动弹模量损失14%的情况下,其水分渗透深度约增30%;掺加引气剂后,即使遭受200次冻融循环,混凝土的整体动弹模量也无明显损失,但200次冻融循环后,混凝土表层出现部分剥落,水分渗透速率及深度均相应增大.在评价混凝土冻融损伤时,除整体动弹模量损失外,还需考虑冻融损伤对混凝土吸水性能的影响.
The effects of freeze-thaw damage on water absorption of concrete with or without air-entraining agent were studied by means of water absorption test and neutron radiation test.The results show that neutron imaging Technology can realize the visual observation and quantitative analysis of the process of water absorption evolution of non-transparent concrete.Unified air-entrained concrete has less frost resistance, and under the condition of 14% loss of dynamic elastic modulus after 10 freeze-thaw cycles, The penetration depth of the water is about 30%. After the air-entraining agent is mixed, even if subjected to 200 freeze-thaw cycles, the whole dynamic modulus of the concrete has no obvious loss. However, after 200 freeze-thaw cycles, Infiltration rate and depth are increased correspondingly.In the evaluation of concrete freeze-thaw damage, in addition to the loss of the overall dynamic modulus, the impact of freeze-thaw damage on the water-absorbing properties of concrete should also be considered.