Cement Stabilized Recycled Aggregate Mixture Anti-erosion Properties

Nowadays semi-rigid base material is often applied to base-course in China, but its anti-erosion performance is insufficient so that the cement concrete pavement wreck and the anti-erosion performance of new cement stabilized recycled aggregate semi-rigid base material is rare reported. According to that, anti-erosion performance of cement stabilized recycled aggregate semi-rigid base material is systematically studied in this paper. The main contents and conclusions of the paper are as follows:1. A new apparatus for anti-erosion experiment was produced by analysis for the advantages and disadvantages of existing apparatuses. The new apparatus has excellent performance, can control the erosion number precisely, test pressure and motor speed. The error of erosion number is 0%, the maximum error of test pressure showed is 1.26%, and the minimum is only 0.42%. Besides, the apparatus has simple operation, low cost, small area, low noise and other advantages. The apparatus is also suitable for other types of base material anti-erosion test, the patent application of which has been approved.2. Through the design of orthogonal experimental determined the running parameters, the best running parameters for the test pressure is 0.5 MPa, motor speed is 200 r / min, the total erosion number of scouring is 24000. In the latter study, a large number of tests have proved that these test parameters are reasonable and scientific. And supporting test method for these parameters is proposed.3. Use the method combined with the rejection law and direct adjustment to adjust the aggregate grade, with the cement dosage of 5% to prepare cement stabilized recycled aggregate semi-rigid base material, the 7d flexural strength of which can satisfy the standard 3～5MPa request, and the experiment results show that the content of recycled aggregate has good Linear correlation between both dry density and moisture content, the correlation coefficient is high. Cement content has obvious effect on cement stabilized recycled aggregate unconfined compression test, unconfined compressive elastic module test, spitting strength test.4. Cement dosage has obvious influence on anti-erosion performance of cement stabilized recycled aggregate semi-rigid base mixture material, which can be enhanced by increasing the cement dosage. Considering the anti-erosion performance and other aspects, we propose that the cement dosage of cement stabilized recycled aggregate semi-rigid base mixture material can not be too high, the range of cement content is about 5% to 6%.5. The best anti-erosion performance with degree of compaction about 98%, 97% and 95% is the degree of compaction 98%, which shows the rule that with the degree of compaction increasing, the anti-erosion performance correspondingly increase. Therefore, we propose that the degree of compaction at least more than 98% apply to high-grade highway cement stabilized recycled aggregate base, which can ensure that the growth of the strength as well as the improvement of anti-erosion performance.6. The result which is about the anti-erosion performance of different grading to cement stabilized recycled aggregate semi-rigid base material shows that cement stabilized recycled aggregate semi-rigid base material of the middle-class limit grading agreed with the request of the code has the highest strength and the best anti-erosion performance.7. As the growth of age, anti-erosion performance improved. In the early days, although the strength of specimens achieves the specifications, the ability of resisting the erosion is weak. After eroding specimens 7320 times, the partial specimen is be eroded. From the age of 90 d, its strength and erosion changes little.8. Using ANSYS to establish model, using the K to indicate the ratio of test erosion and critical erosion, and dividing anti-erosion performance of cement stabilized recycled aggregate semi-rigid base material into poor, medium, good, excellent four levels, which can facilely discovery the distinction of anti-erosion performance between variant materials.9. To guarantee the construction quality of cement stabilized recycled aggregate semi-rigid base material, put forward a comprehensive and systemic quality assurance system and construction guidelines.