Changsha Huanghua Airport Runway Overlay of Asphalt Concrete Mixture Optimization
SMA asphalt mixture is the old airport pavement overlay of asphalt concrete most commonly used technical solutions, combined with the previous runway coagulation Concrete Asphalt design, from the perspective of Asphalt Mixture Design. Laboratory produced using different asphalt modifier, additives (fiber, anti-rutting agent) to form several SMA asphalt mixture. Laboratory tests are to be determined each program's conventional indicators, such as pavement rutting performance. Analysis of test results, the final mixture is to be determined the optimal program. The results showed that SBS star relative linear modifier better road performance, the selection of PAN fiber than the lignin additive mixture of additives on the adhesion, crack resistance, resistance to water damaging have a larger increase, which for the SMA in the application of the runway asphalt concrete pavement to provide a basis for improvement.
Evaluation of Recycled Projects for Performance
iii IMPLEMENTATION STATEMENT iv LIST OF TABLES vi LIST OF FIGURES vi
Experimental study on bond behavior between high-strength grout and deformed steel bars
Abstract Engineers use high-strength grout to connect precast concrete members for its low shrinkage and good fluidity. This paper designed 87 central pull-out specimens using the control variable method to investigate the influence of factors on the rebar-grout bond property such as compressive strength, steel grade, bar diameter, transverse stirrups, and bond length. The test result showed that improving grout compressive strength (85.8 MPa–122.7 MPa) cannot improve the bond strength, which was different from the previous conclusions of concrete pull-out tests. Simplified formulas were presented for calculating the characteristic values of bond strength, residual strength, peak slip, and relative slip of load-holding platform based on parameter analysis. Then, a constitutive model was proposed to predict the full-range bond stress-slip curve of high-strength grout and steel bar specimens from bearing to failure. Finally, FEA models were established to evaluate the applicability and accuracy of the constitutive model.