Abstract

The effect of waterproof membrane and steel reinforcement protection on the concrete bridge deck is modeled. The attention is paid to the durability prediction related to steel reinforcement corrosion initiation based on the chloride penetration. Thus 2-D finite element chloride ingress model is applied. The transient finite element model serves to solve Ficks second diffusion law using the computer tool compatible with the Matlab environment. The model focuses on the transport of chloride ions through a reinforced concrete bridge deck with and without the effect of waterproof membrane and on an estimate of the concentration of chlorides at the reinforcement level or in places with damage to the epoxide coating of the reinforcement. The model allows the incorporation of damage to the waterproof insulation under the asphalt coating. The time to chloride induced onset of corrosion is predicted and results are compared. The effect of water proof membrane reinforcement protection strategy typical for Central Europe and epoxy-coating protection widely used in North-Western United States is evaluated.

Abstract

Abstract

Abstract

A numerical model that accounts for the hydration and aging phenomena during the early ages of concrete curing is presented in a format suitable for a finite element implementation. Assuming the percolation of water through the hydrates already formed as the dominant mechanism of cement hydration, the model adopts an internal variable called hydration degree, whose evolution law is easily calibrated and allows an accurate prediction of the hydration heat production. Compressive strength evolution is related to the aging degree, a concept that accounts for the influences of the hydration and curing temperature on the final mechanical properties of concrete. The model capabilities are illustrated by means of a wide set of experimental tests involving ordinary and high performance concretes, and through the simulation of the concrete curing on a viaduct deck of the Öresund Link.

Abstract

This study analyzes the influence of accelerated aging on the fatigue properties of high-performance thermoplastic matrix composites, specifically carbon fiber-reinforced PEEK. Unidirectional and bidirectional laminates were manufactured from commercial tapes and subjected to xenon arc exposure following Cycle 1 of Method A in the UNE-EN ISO 4892-2 standard. The work combines thermal and mechanical testing to assess polymer matrix degradation and its effect on fatigue behavior. A self-heating approach is also applied as an accelerated method for estimating fatigue performance. The findings aim to enhance the understanding of the durability of these materials under service-representative conditions, with applications in aerospace, automotive, and renewable energy sectors.

Abstract

The rheological properties of Asphalt binder are dependent on the induced temperature during mixing, hauling and compaction. Different literatures and manuals recommend the short term aging property to be checked for period of 85 minutes but during construction on the site this time will not be attained and there is a probability of increase on this time.

The objective of this study is to determine time-dependent aging property of 80/100 penetration grade bitumen. Four specimens of equal weight were extracted from the Penetration grade-80/100 bitumen. The first specimen checked for quality requirements. The other three specimens are aged using Rolling Thin Film Oven for 85, 115, and 145 minutes to simulate the delay during HMA production, hauling, and compaction. Test results indicated as the time of aging increased, penetration and ductility decreased, while, softening point, flash point, and mass loss increased, but a fire point remained constant. Further rheological study using AST and FST test indicate that there is property change on the stiffness and flow property of asphalt binder.