| Edge collapse, honeycomb and surface voids in the slipform paving cement concrete and shrinkage of hardening concrete used in highways are studied in this paper, which is a part of western traffic project, frost resistance of cement concrete, supported by traffic ministry of China. Based on the theory of shrinkage, capillary force theory, the influence of road concrete additives in common use on surface tension of water is studied, and the results show that the influence of water reducer is very small whereas shrinkage-reducing agent and air entrainer can reduce surface tension of solution significantly. The relation between surface tension and additive dosage are non-linear relation. Each additive has an obvious critical micelle concentration (CMC). Surface tension of the solution will not decrease, even increase while the concentration of additive is higher than the CMC. In order to simulate working atmosphere of additives in concrete, the influence of additives on surface tension of calcium hydroxide solution is studied in this paper too. And the influence law is similar to that of water. Surface tension of the calcium hydroxide solution is higher than that of water when the concentration of additive is the same. Studying surface tension of different concrete additives is helpful for additive choice in application and critical micelle concentration (CMC) is reference for the proper dosage of additives.Vibration viscosity coefficient of fresh concrete with additives and mineral admixtures are tested. The results show that water reducer and air entrainer can reduce vibration viscosity coefficient while shrinkage-reducing agent has very small influence on it. Proper quantity of citric acid, sodium glucaonate or carboxymethy cellulose can reduce vibration viscosity coefficient of fresh concrete. Vibration viscosity coefficient decrease with mass percent of fly ash in concrete, but when the mass percent of fly ash is more than 20%, vibration...
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