Strength Characteristics Of Cement Research Articles

Cement quality in thermochemical clinker activation

Improving the quality of cement while reducing the energy costs of its production is one of the most important tasks of the cement industry. Cement properties are determined by the hydration activity of clinker minerals. In turn, the activity of clinker minerals is determined by the degree of disorderliness of the crystal cell. The disorder of the crystal cell depends on the chemical composition of minerals, the type and concentration of modifying additives. It also depends on the modes of clinker synthesis, both during firing and cooling. An effective way of activating clinker minerals is intensive firing of the components of the raw mixture. This method can be carried out by thermal activation of calcium oxide, as well as by bilateral introduction in different zones of the rotary kiln of polycomponent waste of chemical and metallurgical industries The composition and morphology of the main mineral of Portland cement clinker, alite, have been studied by methods of physical and chemical analysis. It was found that the crystals being formed are characterized by a nonstoichiometric composition. Their rapid growth is accompanied by intensive introduction of impurity elements into the crystal cell of the mineral. The hydration activity of clinkers of conventional and intensive firing has been determined. An increase in the rate of hydration of intensive firing clinkers has been established, which leads to an increase in the strength characteristics of cement by 7-10 MPa.

Compressive Strength Evaluation of Ordinary Portland Cement Mortar Blended with Hydrogen Nano-Bubble Water and Graphene.

Abnormal climate changes have occurred all over the world due to greenhouse gases (GHGs). Various countries are targeting emission reductions of GHGs in 2020 and trying to GHGs those in multiple fields. Cement-based structures account for a large part in the construction industry. One ton of carbon dioxide is produced during the manufacturing process for a ton of cement. Therefore, decreasing cement usage is essential for carbon dioxide reduction. However, strength characteristics of cement are necessary conditions to meet the required strength of a structure. Therefore, it is necessary to develop cement substitutes and economic additives. In this study, we proposed an eco-friendly blend ratio by comparing the compressive strength of Ordinary Portland Cement (OPC) mortar and two variations. One was a mortar with a small amount of APTMS-sGO added. The other was a mortar mixed with HNBW (hydrogen nano-bubble water) as an enhanced material instead of ordinary water. The mortar added with 0.1% of APTMS-sGO showed improved early strength compared with OPC mortar. Its strength was enhanced 31.1% by using HNBW as functional water. Strength was improved 20.4% for cement mortar added with Graphene Oxide after reacting with SAM containing APTMS. When the texture of both mortars became denser, early compressive strength at 7 days each was 20.4-31.1% higher than that of OPC mortar. Finally, the strength was increased by 10.2% at 28 days.

Experimental study on strength of cement stabilized clay

This paper describes the effect of factors on the strength characteristics of cement treated clay from laboratory tests performed on cement mixed clay specimens. It is considered that several factors such as soil type, sample preparing method, quantity of binder, curing time, etc. can have an effect on strength characteristics of cement stabilized clay. A series of unconfined compression tests have been performed on samples prepared with different conditions. The results indicated that soil type, mixing method, curing time, dry weight ratio of cement to clay (Aw), and water‐clay to cement (wc/c) ratio were main factors which can have an influence on unconfined compressive strength, modulus of elasticity, and failure strain of cement stabilized clay. Unconfined compressive strength of soil‐cement samples prepared from dry mixing method was higher than those prepared from wet mixing method.