Applied Mechanics and Materials Vols. 587-589

Abstract: Uniaxial compression and bending test of CA mortar, which have six different dosage of emulsified asphalt and the same dry material, is carried out with a electronic universal test machine. It turns out that: when the dosage of emulsified asphalt is lacked, the CA mortar cannot be uniform and stable slurry system; within the range of 300~680 mL emulsified asphalt, slurry state of mortar is good, no separation, and have good liquidity, in this range, with the increasing dosage of emulsified asphalt, compressive strength, elastic modulus and peak strain are gradually reduced, while ratio of bending strength to compressive strength rise at the beginning, then decline within a narrow range; The 1st and 2nd slurry is not stable, they appear separation and the surfaced asphalt, which have similar appearance and mechanical properties to cement mortar, and the last four groups of test results have great difference from the former two groups.

Abstract: The report carries the information about tests of crushed-stone and sand sub-base of pavement reinforced with steel geogrid. As a result we have deformation characteristics of the base of pavement, the effect of reinforcing and deformation regularities of reinforced crushed-stone-sandy structures. We have determined the reinforcing coefficients of steel geogrid.

Abstract: In this study, contrasted rubber modified asphalt and SBS modified asphalt, the mixture of AC-13C, SMA-13 and AR-AC13 are used for compaction test in the range of 120~200 °C as to covering the actual road construction compaction temperature. It can simulated the road compaction performance.The results showed that the temperature is a great influence on the volume parameter of rubber modified asphalt mixture. In the range of 160~180 °C, the void fraction, VMA and VFA of modified asphalt mixture is not sensitive to temperature, improving mixing temperature is not meaningful to improve the quality of compaction. When the temperature dropped to below 160 °C, the VMA rise rapidly, VFA falling rapidly, the increase of void fraction also present a "linear" trend, at this stage to improve mixing temperature can improve the compaction quality.

Abstract: Using cement or lime and cement to solidify the local saline soil. The physical and mechanical properties were comparative analyzed of the curing chlorine saline soil with different ratio, through compaction test and CBR test. The best cure programuse is 6% lime and 6% cement for the saline soil.

Abstract: This paper introduces a real case from construction practice illustrating extensive damage to concrete slit drains, followed by the relevant computer simulation. From the computer simulation and lab tests it follows that the failures of concrete slit drains can be easily caused by deformations of the concrete slabs constituting the surrounding multi-layer road system. Thermally-induced expansions and contractions, as well as concrete shrinkage, produce, in non-dilating connection, stress in the link between the multi-layer road system and the lateral walls of the slit drains. The slit drains are highly sensitive even to a very small malfunction of the expansion joints (e.g. clogging of the slit by solid materials), or their bad installation. It is apparent that failures (cracks) in the slits arise even by the slight compression of a slit drain (to the order of tenths of a millimetre). The analysis presented shows the necessity for a careful installation of expansion joints during the placement of the slit drains into the surrounding multi-layer system, which could induce horizontal pressures on the drains. The study is concluded by recommendations for designers.

Abstract: Concrete slit drains (also known as slot drains) are being used for the draining of highways and roads, as well as for large handling and parking areas. Recently, this system of drainage has become increasingly applied, which does, however, bring with it an increased incidence of failures. The study concentrates on the failures of concrete slit drains, caused by the negative effect of their defective integration into surrounding multi-layer road systems. It starts with a theoretical analysis of the problem, i.e. the negative influence of thermal expansivity of surrounding concrete slabs on slit drains, the impact of their shrinkage, and the co-action of these factors. In addition, it presents a computer numerical analysis of a concrete slit drain loaded by the pressure of adjacent concrete slabs exposed to temperature effects and shrinkage. The most frequent stresses are modelled and the relevant results introduced.

Abstract: Research carried out the highway subgrade disease treatment technology research in volcanic karst crater region through the freeway construction instance in Hainan. And research introduces the hazards of the volcanic karst geology to subgrade, put forward the subgrade disease treatment principles and methods in volcanic karst region, and also defines subgrade disease treatment construction technology program of the uncovered karst disease and the covered karst disease by the scene test of grouting treatment. Research provides the basis of subgrade disease treatment construction techniques and methods in volcanic karst crater region.

Abstract: Porous concrete also be called macropterous concrete or porous lean concrete.As a new base material,it is a lean concrete between cement stabilized macadam and ordinary concrete.Based on Luoyang beltway project,this paper describes the composition design of porous concrete,and discusses the combination of construction machinery,technological process,QCS(quality control specification) and test detection of porous concrete permeable base.Also we do research on many technological parameters such as mixing,paving,molding,maintenance in the construction of porous concrete permeable base.This provides a reference on construction technology and its application.

Abstract: In this paper, digital image processing technology (DIP) is adopted to study the image particle characteristics and mobile trajectory of coarse aggregate. The results show that the DIP particle motion distance accords with the rut test experimental results. The mobile trajectory of coarse aggregates was vertically downward firstly, then to move on both sides at an angle. For dense graded asphalt concrete, the contribution of the asphalt mortar is larger than the coarse aggregates, when resisting vehicular loads.

Abstract: This paper addresses cracks arising on a newly-constructed cement concrete pavement, which need to be treated prior to handover acceptance. They should be renovated by taking different treatment measures, depending on their number, form and location. After the cracks are renovated, the service performance of the pavement can be enhanced and its service life extended.