Effect of Different Pozzolana on Hardening Process and Properties of Hydraulic Binder Based on Natural Anhydrite

Abstract

The study deals with peculiarities of hydration and development of hardening structure as well as durability properties pertaining to composite anhydrite cement pozzolana binder (ACP) with different pozzolana (P). The properties of P have an effect on ACP hydration, structure development and durability properties. This effect is different than that in cement pastes. Investigations were performed with known P: natural opoka (O) and microsilica (MS), also with production waste of mineral wool – cupola dust (CD), which is famous for high fineness and amorphous structure of particles. It was established that the activity of P compounds contained in CD was very high making this waste suitable for ACP as a P component. In ACCD samples, one could observe the most intense hydration; and after a longer inductive period, the development of hardening microstructure was more rapid than in ACMS or ACO; furthermore, a remarkably higher strength was reached. The slowest hydration and structure compacting as well as the lowest strength were found in ACMS samples. It shows that the high pozzolanic activity of P is not the crucial index in evaluation of its effect on ACP properties. Chemical properties of P have a remarkably greater effect; and in case of CD, it is most likely due to reactive alkaline admixtures.

The Effect of Variation of Molarity of Alkali Activator and Fine Aggregate Content on the Compressive Strength of the Fly Ash: Palm Oil Fuel Ash Based Geopolymer Mortar

“…POFA and FA are two readily available industrial by-products; those could be the right choice as pozzolanic materials in the development of geopolymer concrete [13,14]. Zvironaitė et al [15] studied the effect of different pozzolans on the hardening process of binder.…”

Gypsum Compositions Modified with Metallurgical Wastes

“…Based on the studies [10,11], it is assumed that a complex additive based on metallurgical dust and Portland cement will contribute to the formation of poorly soluble products based on calcium hydrosilicates and hydrosulfoferrites. At the same time, metallurgical dust promotes the formation of ettringite not on the surface of cement grains, but in aquatic medium, which prevents body stress and the destruction of the composite [12].…”

The Use of Sapropel in Development of Effective Thermal Insulating Materials

“…For composites with these aggregate different binders are used, such as cement, lime, clay, starch [4]. Most of the binders has flaws: cement industry is a significant CO 2 emitter [5,6], lime does not provide the required strength of the composite [3,7,8], starch is soluble in water. Literature sources about sapropel use as a binder material are very scarce.…”