Abstract This study investigated the optimal water/binder (w/b) and aggregate/binder (a/b) ratios in producing a concrete paving block. The w/b a/b block were optimised using response surface methodology (RSM), considering performances of ultrasonic pulse velocity (UPV), flexural, compressive strengths. Regression modelling was conducted to represent relationships between UPV strength flexural ...

A concrete block retaining wall is supported by its weight. This structure has some advantages, including lower construction costs, a water-permeable that produces less water pressure behind the wall, and more flexible because it can follow ground's contours. Rankine's theory usually used to design this wall. According theory, failure pattern forms an angle of 450 + • /2 with horizontal plane. ...

The handling of mistakes in the mathematics classroom is an area in which only little research is done so far. In mathematics education there are, in fact, several investigations about students’ mistakes from a diagnostic perspective, but hardly any studies on the question how teachers react in concrete mathematics lessons. In this article theoretical aspects and results of different video stud...

Prestressed concrete (PSC) is one of the most reliable, durable and widely used construction materials, which overcomes the weakness of concrete in tension by the introduction of a prestress force. Smart strands enabling measurement of the prestress force have recently been developed to maintain PSC structures throughout their lifetime. However, the smart strand cannot give a representative ind...