Current emissions due to externally applied stress were studied for various materials in the past. This work concentrates on comparative measurements conducted on marble and cement mortar samples. The current emitted and its correlation to the damage development in the samples bulk was studied. Specifically, several experiments were conducted by applying constant stress rate or deformation rate...

Some Problems on High Strength Concrete for Prestressing by Kanji YAMAZAKI (Research Laboratory of Nihon Cement Co., Ltd., Tokyo) This paper describes some problems on high strength concrete studied in our laboratory in recent years. Summary of this report is as follows: (1) In order to make high strength concrete for prestressing, it is necessary to lower the water-cement ratio. But, in the ca...

The effects of polypropylene fibres on mortar and cement-paste cracking were investigated using different amounts fibre fractions eccentric rings under restrained-shrinkage conditions. Eccentric-ring tests conducted to investigate early-age shrinkage cracks. characteristics restricted cementitious materials described by evaluating the time concrete mixtures that are less likely crack. Different...

The addition of sand to cement paste was found to degrade the vibration damping ability, as shown by decreases in both loss tangent and storage modulus under flexure. However, further addition of silica fume more than restored the vibration damping ability, due to the silica fume causing increases in both loss tangent and storage modulus. Silica fume increased the loss modulus of mortar by as m...

Leaching of metals from cement under various environmental conditions was measured to evaluate their environmental safety. A cement product containing clinker, which was produced from cement kiln co-processing of hazardous wastes, was solidified and leaching of metals was characterized using the 8-period test. Concentrations and speciation of metals in cements were determined. Effects of ambien...

This paper aims to contribute to acoustical comfort in buildings by presenting a study about the polymer waste micronized poly (ethylene vinyl acetate) (EVA) to be used in mortars for impact sound insulation in subfloor systems. The evaluation method included physical, mechanical and morphological properties of the mortar developed with three distinct thicknesses designs (3, 5, and 7 cm) with r...

This study presents the result of using melting to recover both industrial sludge slag (the main constituent of which is calcium fluoride) and water works sludge slag as fine aggregate in cement. The main characteristics of both slag and cement mortars were measured to evaluate the feasibility of using slag as aggregate. In this study, the slag replacement ratios were 0, 10, 20, 30, 40, and 50%...

Over the vast Northwest China, arid desert contains high concentrations of sulfate, chloride, and other chemicals in the ground water, which poses serious challenges to infrastructure construction that routinely utilizes portland cement concrete. Rapid industrialization in the region has been generating huge amounts of mineral admixtures, such as fly ash and slags from energy and metallurgical ...

Effects of chemical compositions changes of blended-cement pastes (BCPCCC) on some strength gains of blended cement mortars (BCMSG) were monitored in order to gain a better understanding for developments of hydration and strength of blended cements. Blended cements (BC) were prepared by blending of 5% gypsum and 6%, 20%, 21%, and 35% marble powder (MP) or 6%, 20%, 21%, and 35% brick powder (BP)...