Study On The Adhesion Of Asphalt Mortar And Gravel Aggregate

Compared with the impervious asphalt concrete core wall with the traditional construction speed,low cost,little affected by climate,dam filling quality requirements and low advantage has been widely used in water conservancy and hydropower project,because the heart wall in long-term flooded condition,aggregate and asphalt adhesion quality is an important index to evaluate water stability of asphalt concrete that has a direct impact on safety and reliability and durability of dam.The gravel aggregate is complex in lithology,and it is not easy to determine the acid-base property.Whether the performance of the asphalt concrete made of gravel aggregate can meet the requirements of basic crushed aggregate needs further research and experimental demonstration.In this paper,the quantitative relationship between acid-base and adhesion of aggregate is analyzed from two aspects: aggregate interface and asphalt mortar.The influence of cement on interface and asphalt mortar is studied,and the influence degree of various factors on adhesion strength is analyzed through direct tensile test.Through the above research,the conclusion is as follows:(1)Different p H method to determine the differences between the results of the preliminary determination,lithofacies method applies only to common rocks,alkaline oxide content in the rock considering alkalinity modulus method,more accurate than the Si O2 content analysis method;the photoelectric rock peeling rate consistent with colorimetric method and boiling method,photoelectric colorimetric method measured the peeling rate about 60% corresponding water boiling method adhesion grade 4 and grade 5 boundaries;the rock modulus method measured the alkalinity acidity and photoelectric colorimetric method measured spalling area in order,the more acidic surface asphalt peeling rate is higher.(2)On the one hand,can effectively improve the chemical properties of cement aggregate interface,the gravel and cement asphalt adhesion after treatment increased by 14.6%,while the alkaline powder treated gravel and asphalt adhesion increased by only 0.2%;on the other hand,can effectively improve the structure of cement mortar,adhesion gravel aggregate and cement asphalt mastic asphalt mortar is 27%higher than the powder,gravel aggregate and cement asphalt mortar adhesion than alkaline aggregate and asphalt mortar powder 18.3%,cement can significantly improve the adhesion of asphalt and gravel aggregate.(3)With more limestone cement replacing the penetration of asphalt mortar decreased firstly and then increased,but the softening point increased first and then decreased,showed a parabola,the tensile strength is rising regularity;can effectively improve the cement asphalt mortar and natural gravel aggregate adhesion,cement content more natural gravel the aggregate surface of asphalt mortar peeling rate is small,the amount of cement is only 2%-4%,the adhesion of natural gravel aggregate and asphalt mortar can reach the level of alkaline aggregate.(4)Gravel aggregate crushing residual gravel powder will decrease the performance of asphalt mortar,if taking into account the actual engineering of gravel aggregate crushing residual powder will not exceed3%,the configuration of the cement asphalt mortar and gravel aggregate adhesion decreased only 3%,so the choice of cement can effectively guarantee the quality of asphalt concrete filler.(5)The influencing sequence and the weights of stone and asphalt mastic interfacial adhesion strength for mortar type 1,type 0.783,rock interface processing 0.267 stone;the more acidic,alkaline filler configuration of asphalt mortar on their adhesion strength improvement effect;cement can narrow the p H difference between different stone interface adhesion strength.