The Research On Durability Of Pavement Concrete

The lack of durability of cement concrete pavement is the major factor influencing serviceability of cement concrete pavement and shortening pavement service life. Since the durability of cement concrete pavement includes a lot of aspects, the paper fixes attention on the early cracking resistance of concrete, impact resistance performance and anti-permeability based on the research status at home and abroad.Combining with relevant data, experimental equipment is self-designed, plant test method is introduced to test the cracking resistance of concrete and drop-weight method is used to test the impact resistance performance of concrete in the paper. By a lot of experiments, the paper researches the effect of water-cement ratio, sand rate, coarse aggregate types, gradation of aggregates and addition of fly ash and silica fume to the early cracking resistance of concrete and impact resistance performance, and the experimental results can prove the following points: 1. Minishing the maximum particle size of aggregate can improve the early cracking resistance of concrete and impact resistance performance; 2. Using crushed stone continuous gradation aggregate is good to the impact resistance performance of concrete, but gradation types and facial performance of coarse aggregate have little influence on the cracking resistance of concrete; 3. The impact resistance performance of concrete depresses with the content of elongated and flaky particles in coarse aggregate and mud content increasing; 4. Mixing fly ash into concrete can advance the impact resistance performance of concrete and the cracking resistance greatly; mixing silica fume into concrete can improve the cracking resistance of concrete evidently, but the cracking resistance of concrete is reduced badly; 5. The impact resistance performance of concrete minishes with water-binder ratio growing; the cracking resistance of concrete depresses with cement content in concrete adding. On the basis of the laboratory experiments, the paper analyzes how material and configuration parameter influence the durability of concrete, and put forwards principles to select material of pavement concrete. Meanwhile, the paper analyzes the deficiency of mix design method of ordinary concrete ,in addition, proposes a method for durability design which is suitable for pavement concrete. Combined with Hunan S103 road reconstruction engineering, experimental road is paved and some spot experiments have been done, based on laboratory experimental results. Mix proportion of concrete is designed making use of the mix design method of concrete. On the basis of construction, appropriate techniques and quality controlling measures are advanced. After one year's running, the road is detected and the result shows that the pavement is in good condition without crack.