四、路面用混凝土材料工艺目前各国普遍认为路面用混凝土必须具有较高的抗压、抗弯拉、抗磨耗和抗冻强度,而且还要能抵抗融冰化雪盐类的侵蚀作用。所规定的28天强度标准,对抗压一般不小于400公斤/厘米~2,对抗弯拉则不少于40～55公斤/厘米~2。但因所用试件的形状和尺寸以及试验方法和龄期等不尽相同,故难于相互比较。西德总结出下列规律: Fourth, the road with concrete material technology At present, countries generally believe that concrete pavement must have high compressive, anti-bending, anti-wear and antifreeze strength, but also to resist melting ice snow salt erosion. The prescribed 28-day intensity standard is generally not less than 400 kg / cm 2 against compression and not less than 40-55 kg / cm -2 against bending. However, due to the shape and size of the specimen used and test methods and age are not the same, it is difficult to compare with each other. West Germany summed up the following rules: