Advanced Materials Research Vol. 1054

Abstract: The results of research of mechanical properties and selected other characteristics influencing durability of cement concretes containing cement substitutes were presented. Cement concretes performed with conventional fly ash, fluidised fly ash and their mixture were investigated. The obtained results were compared with findings registered for two types of concrete performed without cement replacements and with cement concrete containing silica fume. The results have shown that cement concrete with predetermined 28-day compressive strength of about 50 MPa and good workability may be obtained using different cement replacements. Generally, these cement concretes exhibited also favorable properties related to concrete durability, i.e. low permeability and sorptivity, and significant reduction of chloride migration coefficient. Favourable results were obtained for cement concrete containing mix of conventional and fluidised fly ashes: good workability, compressive strength after 28th day exceeding 50 MPa, low permeability of water, and low sorptivity, as well as low coefficient of chloride migration. These features were similar as for cement concrete containing silica fume.

Abstract: This paper describes influence of time and temperature of heat curing on progress of mechanical characteristics of concrete mixtures based on alkali activated fly-ash (POPbeton). One of the major impacts for the correct treatment of alkaline activation is the quantity of heat energy in a given time period which is supplied during activation. The paper describes the dependence of progress of compressive strength of POPbeton on the time and temperature of heat curing. It was assembled a predictive model which describes the dependence of the supplied heat energy over time on the resulting properties of POPbeton. The result is a tool that can predict the resulting values of mechanical characteristics of test samples of POPbeton.

Abstract: The article deals with preparation of Portland cements from raw material powder with reduced carbonated component. This component is replaced with fluidised fly ash. With prepared model cements tests of basic technological properties were carried out.

Abstract: This paper describes basic properties of materials composed of fly ash produced during fluid burning. This material is based on alkali-activated fly ash which contains a portion of fly ash produced during fluid burning. Firstly the physical and chemical properties was described for each type of fly ash and fly ash mixture. The new materials composed of fly ash mixture and fly ash may have the similar mechanical and physical properties. The work focused on findingan appropriate technological procedure, the optimum composition of mixtures. Long-term stability was simulated by means of accelerated aging of these materials.

Abstract: Waste ceramic powder coming from grinding the ceramic bricks disposed on demolition depot is investigated as partial Portland cement replacement in blended binders. For the milled ceramic powder, measurement of specific surface area (SSA) and particles size distribution is done. Its chemical composition is accessed using X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) analysis. The blended binders containing ceramic powder in an amount of 8, 16, 24, 32, and 40% of mass of cement are used for the preparation of cement pastes which are then characterized using the measurement of basic physical properties, mechanical properties, hygric and thermal properties. The obtained results show that an application of 8 and 16% ceramic powder in the blended binder provides sufficient mechanical properties of the pastes with relatively low hygric transport properties. From the thermal performance point of view, the incorporation of ceramic powder decreases the heat transport in all the tested pastes. This makes good prerequisites for future research that will be focused on the development of new types of cement-based composites with incorporated ceramic waste powder.

Abstract: Paper deals with utilization of fine ground ceramic powder as a supplementary cement addition. Present work follows previous research focused on the basic physical and hygric properties of cement composites with ceramic powder application. Present work introduce rheological, mechanical and fracture properties of cement pastes investigated during maturation at time 7 days. Presented data are added by results of pore characteristic having essential impact to final properties. Obtained data confirm previous assumption of retarding of hydration process, but final fracture properties indicate increased durability of cement pastes with fine ceramic powder addition.

Abstract: This article is focused on the utilization of metashale as a supplementary cementitious material in concrete. Metashale as well as metakaolin is a product originating in the burning of clay materials, but in metashale production, the raw material is shale (aluminosilicates with granularity up to 0.02 mm). Four mixtures with cement replacement ranging from 0% up to 60% are designed and their properties are examined. Basic physical properties, mechanical strength, as well as hygric transport properties are measured and evaluated, in order to determine the influence of metashale on concrete properties. Experimental results show that for low amounts of cement replacement, metashale admixture leads to the improvement of studied material characteristics. When the material contains 40% of metashale, studied characteristics have almost similar values as the reference material. The worst values of measured properties are obtained for the replacement level of 60%. Nevertheless, all studied materials have appropriate properties to be applicable as high performance concrete.

Abstract: The possibilities of utilisation of ceramic powder as supplementary cementitious material are the matter of the presented study. The finely ground ceramic powder originates from the grinding process of thermal insulating brick blocks and shows pozzolanic properties. For the determination of its influence on concrete properties, five mixtures with different percentages of cement replaced by ceramics are designed. The bulk density as well as matrix density are found to decrease with the increasing dosage of waste ceramic material, while the open porosity increases. The compressive strength exhibits a small decrease with the growing amount of cement replacement. The measurement of thermal conductivity shows that by adding ceramic powder the thermal insulating abilities of studied concrete are improved.

Abstract: In the article the possibility of utilization of two waste materials: Recycled Concrete Aggregate (RCA) fraction 0-2 mm and Class C fly ash (from lignite burning power plant) in Controlled Low-Strength Material (CLSM) was presented. The research covered twelve different mixtures. The mixtures differed in cement and fly ash content as well as content of the fine aggregate. As a fine aggregate 0-2 mm fraction of RCA or river sand were used. The results showed that use the fine fraction RCA instead of sand does not cause technological problems and allows, depending on the needs, obtaining the material with different properties and a wide range of applications.

Abstract: Lime plasters containing waste brick powder in different quantities (10%, 30%, and 50% of mass) as a partial replacement of silica sand and lime are studied. A common lime plaster is used as a reference. Experimental investigations include the measurement of basic physical properties (water vacuum saturation method and helium pycnometry), pore distribution (mercury porosimetry) and water vapor transport properties (cup method). The open porosity and water vapor diffusion coefficient are found to increase with the increasing brick powder content.