In this study, we evaluated a two-step process for detoxification of waste roofing slate, involving cement hydrate removal and low temperature detoxification using oxalic acid. These treatments were conducted on raw material and intermediate product, respectively. Cement hydrate removal effectively eliminated most Ca-containing cement hydrate components from the raw material under the following...

background: cement production is associated with heavy metal emissions and environmental pollution by cement dust. the degree of contamination of drinking water sources by major and trace elements present in cement dust generated by united cement factory (unicem) is still uncertain. this study estimated the element content of ground and surface water samples (hand-dug wells, boreholes and strea...

In this study, first by surveythe parameters affecting the compressive strength, such as water to cement ratio, cementgrade, silica fume to cement percentage, and the various ratios oflight weight aggregate LECA, to total aggregate, Taguchi method is used, to test 9 mix designsobtained the mix design optimization. Since lightweight concrete is brittle like normal concrete, to resolve this probl...

reactive powder concrete (rpc) is an ultra high performance concrete which has superior mechanical and physical properties. the rpc is composed of cement and very fine powders such as crushed quartz (100–600 μm) and silica fume with very low water/binder ratio (w/b) (less than 0.20) and super plasticizer (sp). the rpc has a very high compressive and tensile strength with better durability prope...

Thermal conductivity plays a significant role in controlling thermal cracking of cement-based materials. In this study, the cement paste at an early age was measured by hot plate method. The test results showed that decreased with increase water/cement ratio and curing age. Meanwhile, multiphase model for proposed used to study influence saturation temperature on paste. To determine parameters ...

ABSTRACT: Overall plant growth and microbial biomass can be effected by dust accumulation. The chloroform fumigation-extraction method was used to evaluating the effect of cement dust pollution emitted from Kurdistan cement factory on soil microbial biomass carbon. Chlorophyll content (a, b and total) of plants species was measured in different distance from cement factory. Mic...

A newly developed ultrasound method that acquires at the same time both reflected and transmitted P-waves, different angles, using two immersion transducers of 0.5 MHz central frequency, is described in this present study. This non-destructive allows calculating longitudinal transverse velocities, thus, Young modulus, so its evolutions followed domain. The closely correlation between evolution ...

The paper compared the effect of additives such as FeSO4.7H2O and SnCl2.2H2O on reduction of water soluble Cr(VI), in ordinary Portland cement (43 grades). The determination of water soluble Cr(VI) from cement samples was precisely conducted by DPC-Spectrophotometer technique. The compressive strength testing of the cement mortar samples was carried out. In addition, hydration properties of cem...