Concrete is the extensively used construction material in the world. However, environmental concerns both in terms of damage caused by the extraction of raw material and CO2 emission during cement manufacture have brought pressure to reduce cement consumption by the use of supplementary materials. The utilization of calcined clay, in the form of metakaolin (MK) in concrete has received consider...

conclusions according to this study, pumice powder and slurry used in dental laboratories of hamadan are contaminated. therefore, the laboratory staff should be aware of the hazards posed by the presence of pathogens in dental laboratories. materials and methods forty specimens, including 20 pumice powders and 20 pumice slurries were collected from 10 randomly selected dental laboratories and i...

Pumice rafts are floating mobile accumulations of low-density pumice clasts generated by silicic volcanic eruptions. Pumice in rafts can drift for years, become waterlogged and sink, or become stranded on shorelines. Here we show that the pumice raft formed by the impressive, deep submarine eruption of the Havre caldera volcano (Southwest Pacific) in July 2012 can be mapped by satellite imagery...

Self compacting concrete (SCC) is an innovative development of conventional concrete, which requires high binder content to increase its segregation resistance. This paper presents a comparative study on the use of different materials as binder content in SCC and their effects on the workability and strength properties are checked. Different combinations of Fly ash, Metakaolin and Saw dust ash ...

Concrete a composite material made from cement, water, fine aggregate and coarse aggregate. But present researchers are in interest of finding new cement materials by waste materials or waste products produced from industries which are harmful to environment. The present paper deals with partial replacement of cement with quarry dust and metakaolin which are having silica used as admixture for ...

The objective of this study is to examine the effect of substitution of cement by three different mineral additions, on the mortar rheological and mechanical properties. This experimentation, considers the fineness of mineral additives with a constant workability. Ordinary Portland Cement was partially replaced by different percentages of slag, pozzolana and metakaolin of 10, 20 and 30%. The ob...

A novel concept in internal curing of High Performance Concrete is based on dispersing very small, saturated lightweight aggregates (LWA) in the concrete, containing sufficient water to counteract self-desiccation. With this approach, the amount of water in the LWA can be minimized, thus economizing on the amount of the LWA. In this study, the pore structure of different size fractions of pumic...

application of superabsorbent material is one of the new methods for moisture storage in the soil. this research was performed in the khajeh research station on the basis of randomized complete block design with three replications in the plots with dimension of 4×5 meter for investigate the effect of different amounts of pumice on water retention capacity in the soil, growth and of spring saffl...