We are concerned by the design of a non destructive ultrasonic method quantifying porosity of cover concrete. Modification of porosity is a major cause of reinforcing bar corrosion that induces bar swelling and macro-cracks which may cause the ruin of the structure. It is then necessary to characterize the porosity in the first cm above the steel bars. For surface measurements the most energeti...

Economically optimal management of a continuous cover forest is considered here. Initially, there is a large number of trees of different sizes and the forest may contain several species. We want to optimize the harvest decisions over time, using continuous cover forestry, which is denoted by CCF. We maximize our objective function, the expected present value, with consideration of stochastic p...

For concrete bridge projects in marine environments, attention must be paid to the reinforcement corrosion problems caused by chloride intrusion. As kinds of functional admixtures, which can reduce the reinforcement corrosion rate, corrosion inhibitors are becoming very popular in China in new bridge projects. Corrosion inhibitors cover both inorganic and organic inhibitors. Nitrite is represen...

This study investigates the mechanical behavior of steel fiber-reinforced concrete (SFRC) beams internally reinforced with steel bars and externally bonded with carbon fiber-reinforced polymer (CFRP) sheets fixed by adhesive and hybrid jointing techniques. In particular, attention is paid to the load resistance and failure modes of composite beams. The steel fibers were used to avoiding the rip...

This is a small version of a paper published at the ISW2000 in Wollongong describing only the new codec for embedding and extraction of the additional information and some experimental results. 1 An adaptive steganographic framework In this section, we introduce a new hybrid steganographic approach. The presented framework is distinguished from previous approaches by a greater flexibility facin...

in this paper the fuzzy structural reliability index was determined through modeling epistemic uncertainty arising from ambiguity in statistical parameters of random variables. the first order reliability method (form) has been used and a robust genetic algorithm in the alpha level optimization method has been proposed for the determination of the fuzzy reliability index. the sensitivity level ...

One of the most crucial factors affecting the service life of reinforced concrete (RC) structures attacked by aggressive ions is reinforcement corrosion. As the steel corrosion progresses, crack propagation in concrete medium endangers the serviceability and the strength of RC structural members. In this study, a nonlinear mathematical model for determining the displacement and stress fields in...

Corrosion of the steel reinforcement in concrete requires manual and costly repair procedures to prevent premature failure of constructions. Although preventive measures during the construction phase are often implemented but early corrosion may still occur. The primary reason for premature corrosion is crack formation in the concrete cover. Larger cracks as well as a network of finer cracks al...

Concrete is a brittle material. The lack of durability of concrete infrastructure has been a recognized concern. Research in fiber reinforced concrete (FRC) often addresses the issue of material brittleness. However, the translation of improved ductility of FRC into infrastructure durability is often overlooked. This paper explores the concept of elevating the ductility of high performance fibe...

A corrosion sensor for monitoring the corrosion state of cover mortar was developed. The sensor was tested in cement mortar, with and without the addition of chloride to simulate the adverse effects of chloride-contaminated environmental conditions on concrete structures. In brief, a linear polarization resistance method combined with an embeddable reference electrode was utilized to measure th...