Effect of type of mixing water and sand on the physico–mechanical properties of magnesia cement masonry units

AbstractThis study has been conducted to investigate the influences of sand addition and mixing waters with different ratios on the physico-mechanical properties of magnesium oxychloride cement (MOC) masonry units. Three mixtures (M, MI and MII) were prepared to make magnesium oxychloride cement from the sand dunes as a filler material with some different additives. The mixture (M) was prepared by seawater instead of tap water in the mixing process, other mixtures (MI & MII) used drinking water. The physico-mechanical properties were studied in means of determination of bulk density, water absorption and compressive strength of the hardened MOC specimens cured in air at the lab ambient conditions for 3, 7, and 28days. It was recognized that the compressive strengths decreased with the increase of sand dunes content. The specimens of the all cured mixtures fulfilled superior properties compared with the required limits for concrete and limestone masonry units of a heavy density type. Also, it was found that using of the seawater leads to increase the physico-mechanical properties of the MOC specimens and can be used as mixing water in the manufacture of masonry units instead of the traditional drink water after ensuring of the other demanded governing properties

The Feasibility of Using Marble Cutting Waste in a Sustainable Building Clay Industry

This study evaluates the feasibility of stabilizing clay bricks with marble cutting waste (MCW). This waste is currently discarded in huge quantities as sludge resulting from the sawing of marble blocks to slabs and the processes of disposing of grinding and polishing marble in landfills located around the marble processing factories in the Shaq El-Thoban industrial zone, Cairo governorate, Egypt, which causes negative impacts on the environment, health, and sustainable development. Experimental investigations were carried out to explore the effect of the addition of MCW in different clay–base mixes using varying percentages of up to 20% at the expense of the hydrated lime. Cement, hydrated lime, and MCW are the three types of solidification agents used, and clay and sand were also added in the formulations of the unfired clay brick specimens. Laboratory cylindrical stabilized and compressed specimens were made; then, they were cured in a humidity chamber for two weeks and four weeks. Afterwards, they were air dried, tested, and evaluated according to the Egyptian code for the building by the stabilized and compressed earth soil (ECBS, 2016). To enhance the durability of the cured specimens, transparent silicon-based paint was used. The results demonstrated that the optimum content of marble sludge waste (MCW) was 15% when used as replacement for hydrated lime in the production of stabilized clay brick. For all of the samples, the use of silicon-based paint was found to improve the strength and water resistance of the stabilized clay bricks. The use of local waste materials as a substitute for a hydrated lime binder reduces both the cost and environmental impact associated with block production

Engineering and mineralogical characteristics of stabilized unfired montmorillonitic clay bricks

This paper presents engineering and mineralogical characteristics of stabilized unfired montmorillonitic clay bricks treated by different curing methods. Quicklime (up to 30 wt.%) and Portland cement (up to 15 wt.%) at different proportions were used as stabilizers to Egyptian montmorillonitic clay in clay-based mixtures. Sand was used in the formulations of the unfired clay brick specimens. The formulated clay specimens were treated by moisture and spray techniques until 90 days of curing. The laboratory unfired stabilized clay specimens were identified using X-ray diffraction technique. In addition, physical and mechanical properties were measured according to the Egyptian Standard Specification (ESS) 1234-2005 and evaluated in accordance with the Egyptian Code for Building Units (ECP) 204-2005 to ensure the quality and impact of the made unfired clay specimens. The quantification of the formed phases demonstrated a detrimental effect of calcium silicate hydrates (C-S-H), portlandite (Ca(OH)2) and calcite (CaCO3) phases in the studied samples. The physico-mechanical results of the specimens cured by the moisture method were higher than those treated by the spray of the same sample. In all cases, the test results suggested that cement amended specimen properties rather than lime. Moreover, as explained from the obtained physico-mechanical properties, calcium hydroxide generated from the hydration of cement is more reactive than that from the hydration of the added lime. Also, it is recommended to use the suitable mixture for rural building construction in tropical countries

The Influence of Aggregate Type on the Physico-Mechanical Properties of Magnesia Cement Pastes

Abstract The work concerns physico-mechanical properties of magnesia cement pastes-specially magnesium oxychloride (MOC

The composition and activation aspects of El-Fayoum clays for using as a drilling fluid

The local consumption and the high importation cost of imported bentonite to Egypt led to find local substitute solutions for economical aspects. Hence, this paper presents the composition and activation capability of clays collected from the claystone quarries in Kom Oshim area at El-Fayoum province, Egypt for their application as a drilling fluid (water-based mud). It is an attempt to minimize the importation cost of the imported bentonites to Egypt by a local solution and maximize the usage of the studied clay sediments. The physical, chemical, thermal and mineralogical characteristics of five Egyptian clay samples were studied. The rheological properties of the prepared slurries from these samples and their activation characterization during studying the influence of NaOH and POLYPAC-R polymer as activators were investigated. It was found that the non-activated samples cannot be used as a drilling mud but it could be after the activation process where some significant changes in the rheological properties were observed. The experimental results revealed that the activated fitted samples may express as medium grade bentonitic clay and this type of clay can be used as a drilling fluid for shallow depth wells