Analytical Investigation for Determining Ressilient Modulus for Interface Layer of Aggregates
Quality road aggregates have become rare and costly in many places in India due to massive construction activities required for the development of new infrastructure facilities. The pavement industry seeks ways of improving lower quality materials that are readily available for use in roadway construction. Cement treatment has become an accepted method for increasing the strength and durability of soils and marginal aggregates. However, cement-stabilized bases can also be the source of shrinkage cracks in the stabilized base layer, which can reflect through the asphalt surface. Introducing “Interface Layer of Aggregates (ILA)” between stabilized base and bituminous concrete (BC) layer appears to be very favorable. The present paper presents the determination of resilient modulus of ILA using FPAVE software. Figures have been developed to determine resilient modulus, varying the CBR value, the thickness of cement treated base and the thickness of interface layer of aggregates which is useful to determine the pavement thickness for cement treated base.
Analytical design of flexible pavements
A flexible pavement combines layers of generally different materials in a structural system designed to withstand the cumulative effects of traffic and climate to the extent that, for a predetermined period, the foundation or subgrade is adequately protected and the vehicle operating costs, safety and comfort of the road user are kept within tolerable limits.
A New Vacuum Pressure Infiltration CFRP Method and Preparation Experimental Study of Composite
In order to prepare a carbon-fiber-reinforced polymer composite (CFRP) with ideal microstructure and properties, a new vacuum pressure infiltration CFRP method is proposed based on an analysis of existing CFRP preparation process methods. Research on composite material preparation systems was carried out by using this new method principle. The system mainly includes a fiber pre-forming module, a vacuum heating infiltration module, a hot-press curing molding module, and a data acquisition control module. Under the conditions of natural curing at 0 MPa + 6 h + 25 °C, vacuum heating curing at –0.05 MPa + 30 min + 80 °C, and hot-press curing at 0.7 MPa + 5 min + 50 °C, a two-dimensional (2D) CFRP with excellent microstructure and properties was successfully prepared. Observing the microstructure of the prepared composite material, it can be found that the inside of the composite material was sufficiently and uniformly infiltrated, and common preparation defects such as holes and delamination were effectively controlled. Through the performance test, the bending strength of the material reached 790 MPa.