JSTI Group

Waste glass as a solid waste is urgently needed to utilize and alleviate the shortage of natural aggregate.In this paper, a styrene-butadiene rubber (SBR) modified emulsified asphalt microsurfacing mixture was prepared by partially replacing basalt aggregate with waste glass, and the interlayer shear resistance and night visibility were explored.The optimum content of SBR was determined by evaluating the properties of SBR-modified emulsified asphalt.The wet track abrasion and load wheel test were chosen to optimize the content of asphalt.Moreover, Leutner shear strength was measured to characterize the interlayer shear resistance, and the night visibility was certified through qual. and quant. methods.The exptl. results indicate that modified emulsified asphalt exhibits good properties when the dosage of SBR is 4%.The addition of waste glass exerts a certain weakening effect on interlayer shear resistance of the microsurfacing mixture, but the adverse impact could be neglected when the content of coarse and fine waste glass is less than 15%.The night visibility is improved significantly when the waste glass is added; the retroreflection coefficients are 52.2 and 45.7 mcd/lx/m², resp., when the content of waste glass fine aggregate and waste glass coarse aggregate reaches 20%, and the reflective effect brought by waste glass fine aggregate is more remarkable.The application of waste glass in the microsurfacing mixture realizes the resource utilization of solid waste, provides a safe environment for driving at night, and achieves the effects of traffic guidance and landscape.

Aromatics constitute the highest proportion among the four asphalt components.The existing literature contains over 20 types of small mols. used to characterize asphalt aromatics, which presents a challenge in constructing asphalt mol. models.In this investigation, quantum chem. calculations were employed to determine the mol. morphol., mol. polarity, and IR spectrum indicators of asphalt aromaticsBased on principal component anal. and hierarchical clustering, statistical anal. of the aforementioned indicators was conducted to present a recommended scheme for selecting representative mols. of aromatics, thereby reducing the difficulty of constructing asphalt mol. models.The results indicated that N2 was recommended as the representative mol. for aromatics with high mol. weight and long alkane chains, while N3 was recommended as the representative mol. for aromatics with low mol. weightBased on the variations in substituents of aromatics, it was advisable to select one or more of N7, N10, N14 - N16, and N19 as representative mols.The investigation guided the selection of aromatic representative mols. in the construction of asphalt mol. models.For major projects with test data, representative mols. could be adjusted according to the test data.

Stress laminated timber (SLT) deck is assembled using timber (lumber or glulam) components placed side by side and stressed together, which has the advantages of easy prefabrication and good cost performance.This work presented an exptl. investigation of bending tests performed on SLT slabs.Several parameters, including prestress levels, distance of pre-stressing bars, and the existence of self-tapping screw (STS) reinforcement, were taken into consideration.To reinforce the compressive property of timber perpendicular to the grain, the STSs were placed under the anchor plate of the pre-stressed bars.The exptl. results were analyzed and discussed in terms of failure modes, ultimate bearing capacity, ultimate strain, and bending stiffness.It was found that the SLT slab showed satisfactory composite action as well as residual bearing capacity.The pre-stress levels showed an obvious effect on the load bearing capacity and relatively slight effect on the bending stiffness.