Study On Road Performance Of Guangxi Sandstone Asphalt Concrete

In order to make full use of local resources of Guangxi sandstone,sandstone in Guangxi to promote the application of asphalt concrete pavement,this paper studied a lot of test room on the physical and mechanical properties of sandstone,sandstone asphalt concrete water stability,fatigue performance and dynamic modulus,and indoor paving a road test,the 1/3 accelerated the loading test,achieved satisfactory results.The crushing value of the sandstone was tested at a constant temperature of +180°C,and the effect of freeze-thaw cycle on the crushing value,polishing value and wear value of the sandstone gravel was investigated.Marshall compaction will affect the gradation curve of sandstone asphalt concrete,and the mixture will be refined;the best ratio of oil and stone will be obtained by Marshall method.Using water boiling method,the adhesion of aggregate and asphalt was obtained: limestone> sandstone> granite.The residual strength ratio of crushed stone AC 4.6% and 5.0% sandstone AC-13 asphalt concrete does not meet the water stability requirements;the ratio of oil to stone 6.3% SMA-13 satisfies the water stability residual strength ratio meets the water stability.The test method and procedure for the ratio of residual energy of indirect tensile in Brazilian roulette were developed,and sandstone asphalt concrete was evaluated with three residual energy ratios.With the residual energy ratio,a second energy treatment method is recommended,and the residual energy ratio is more suitable.The dynamic stability of the sandstone-asphalt concrete with a ratio of crushed stone to sandstone is 6.488 times/mm.The dynamic modulus master curve of the sandstone-asphalt concrete with a ratio of 4.4% is obtained,which provides design parameters for the asphalt pavement design;and the sandstone asphalt concrete undergoes freeze-thaw cycles.After that,the residual dynamic modulus ratio was 71% to 76%,and the phase angle increased by 5% to 10%.AC-13 sandstone asphalt concrete has strong fatigue resistance.A three-wheel accelerating loading tester was designed and manufactured.The change law of the friction coefficient of the sandstone asphalt concrete after tri-annular acceleration loading was obtained.The effects of high-temperature and wet conditions on sandstone asphalt concrete in Guangxi were simulated by MMLS3 accelerated loading test system and 80°C hot water environment conditions.In the test section,160,000 rounds of accelerated loading tests were performed,and the changes in the friction coefficient and modulus of the pendulum were obtained.The law of change;after 160,000 accelerated loadings,the strength of sandstone concrete was reduced by 11.3%,and the residual strength ratio was 88.7%,meeting the requirements for water stability.Further,we should further summarize the construction technology of sandstone asphalt concrete and observe the decay law of sandstone asphalt concrete pavement performance through field test and construction and observation.