A new patented lightweight aggregates is tested. This type is given the name Flashag. The only solid raw material used to manufacture these aggregates is fly ash. The aggregates are sintered but not pelletized and the process is easy and inexpensive. This paper describes these patented aggregates and compares them with other lightweight and normal-weight aggregates that are used for concrete. T...

We tested the setting time of cement, slump and compressive and tensile strength of 54 triplicate cubic samples and 9 cylindrical samples of concrete with and without a Super plasticizer admixture. We produced concrete samples made with drinking water and treated domestic wastewater containing 300, 400 kg/m(3) of cement before chlorination and then cured concrete samples made with drinking wate...

The performances of cementitious materials as well as the efficiency of construction are adversely affected at high temperatures. Previous studies have already demonstrated that ultra-fine (alccofine) material accelerates the hydration of cement particles and subsequently improves the mechanical and durability properties of the concrete at normal temperature. Moreover, at higher temperatures th...

rice husk ash (rha) is natural pozzolan containing reactive silica and/or aluminum. when the material is mixed with lime in powdered form and in the presence of water, it will set and harden like cement. this work uses osadebe’s optimization model to optimize the shear modulus of concrete made from rha. the strengths predicted by the model are in good agreement with their corresponding experime...

Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass ...

This research paper describes the study of combined effect of Fly Ash (FA) and Rice Husk Ash (RHA) on properties of concrete as partial replacement of Ordinary Portland Cement (OPC). These by-products are having high pozzolanic reactivity. In this research, the composition of mix was used with 10% RHA along with 10, 20 and 30% FA as partial replacement of cement. In this study, the compressive ...

Characteristics of produced concrete become changedthrough changingthe characteristics of materials constituting the concrete. These changes include: The quality of cement, the real ration of water to cement: with neglecting the further water within the aggregates or lack of that, the consideredratio fluctuates and the characteristics of the aggregate which are related to the following dimensio...

The production of cement results in emission of many green house gases in atmosphere, which are responsible for global warming. Hence, the researchers are currently focused on use of waste material having cementing properties, which can be added in concrete as partial replacement of cement, without compromising on its strength and durability, which will result in decrease of cement production t...

Rice Husk Ash (RHA) is natural Pozzolan containing reactive silica and/or aluminum. When the material is mixed with lime in powdered form and in the presence of water, it will set and harden like cement. This work uses Osadebe’s optimization model to optimize the shear modulus of concrete made from RHA. The strengths predicted by the model are in good agreement with their corresponding experime...