Influence of cement on low-temperature property of granite asphalt mixtures
Combined with the application of granite asphalt mixtures in the pavement project along the Ma-Wu Expressway. In this paper, the amount of 20%, 40%, 60%, 80% cement was in equivalent replacement of common filler. The effects of cement on low-temperature property of granite asphalt mixtures were investigated by indirect tensile strength and three-point bend test, obtained the variation of cement with different admixture amounts influence on granite asphalt mixtures, than the optimum mix amount has been found. Experimental results showed that the cement additive improved the low-temperature property and the optimum mix amount of cement was 40%∼60%, which possesses guiding significance for ensuring bituminous pavement project quality.
EVALUATION OF INDIRECT TENSILE TEST (IDT) PROCEDURES FOR LOW-TEMPERATURE PERFORMANCE OF HOT MIX ASPHALT
This report presents the findings of a research project to evaluate the use of the indirect tensile creep and strength test procedures in AASHTO Standard Method of Test T322-03 in mixture and structural design methods for hot mix asphalt. The report will be of particular interest to pavement design and materials engineers in state highway agencies, as well as to materials suppliers and paving contractor personnel who are responsible for the design and evaluation of hot mix asphalt mixtures and pavements.
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.