Tereza Kulovaná

Characterization of composite materials based on cement-ceramic powder blended binder

Characterization of newly developed composite mortars with incorporated ceramic powder coming from precise brick cutting as partial Portland cement replacement up to 40 mass% is presented in the paper. Fine ceramic powder belongs to the pozzolanic materials. Utilization of pozzolanic materials is accompanied by lower request on energy needed for Portland clinker production which generally results in lower production costs of blended binder and lower CO2 emission. In this paper, the ceramic powder is used in cement based mortar composition in amount of 8, 16, 24, 32, and 40 mass% of cement. Chemical composition of ceramic powder is analyzed by X-Ray Fluorescence and X-Ray Diffraction. The particle size distribution of ceramics is accessed on laser diffraction principle. For 28 days cured mortar samples, basic physical and mechanical properties are experimentally determined. The obtained results demonstrate that ceramic powder has potential to replace a part of Portland cement in composition of cement based...

Reuse of Waste Ceramic Powder with a High Content of Amorphous Phases as Partial Replacement of Portland Cement

A possible use of waste ceramic powder as a partial replacement of Portland cement in blended binders is studied. For the ceramic powder, originating from the contemporary hollow bricks production, the measurement of chemical composition is done using XRF and XRD analysis. The particle size distribution of ceramics and cement is accessed on the laser diffraction principle. 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 and mechanical properties. Experimental results show that an application of 16% waste ceramics in the blended binder provides sufficient mechanical properties of the paste. 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.

Engineering properties of composite materials containing waste ceramic dust from advanced hollow brick production as a partial replacement of Portland cement

Waste ceramic dust originating in the advanced hollow brick production is applied as a supplementary cementing material replacing a part of Portland cement in concrete. The measurements of mechanical and fracture-mechanical properties, water vapor and liquid water transport parameters, thermal conductivity, specific heat capacity, and freeze/thaw resistance show that the ceramic dust application does not affect negatively the properties of the analyzed concretes over the whole studied Portland cement replacement range up to 40% by mass. The achievement of such a high limit for the ceramic dust application can be attributed, besides the pozzolanic reaction being initiated already during the time period of 7 to 28 days, to the positive effect of the excess ceramic dust in the mixes with a high volume of uniformly distributed air voids. The part of the ceramic additive which cannot participate in the hydration and pozzolanic reactions due to the lack of available Ca2+ acts, apparently, as fine aggregate partially filling the voids, thus contributing to the compaction of the hardened mixes and compensating, to a certain extent, the factual decrease of the amount of binder.

Applicability of contemporary ceramic bricks for the reconstruction of historical masonry

Two historical ceramic bricks originating from the beginning of 20th century and a contemporary poorly burnt ceramic brick are studied, in order to assess a possible application of current bricks in the renewal of historical masonry. For the researched materials, basic physical, mechanical and hygric properties are analyzed. Among the basic physical properties, determination of bulk density, matrix density, total open porosity and pore size distribution is done. The mechanical performance is characterized by compressive strength and Young’s modulus. The moisture transport properties that represent crucial parameters for the durability of tested materials are described by water absorption coefficient and sorptivity, whereas the measurements are done for the penetration of pure water, as well as 1M NaCl water solution. The obtained data indicate that the studied currently produced ceramic brick can be successfully used at the reconstruction of historical buildings.

Red Ceramic Wastes: A Calcined Clay Pozzolan

The properties and hydration of blended cements containing from 8 to 40 % by mass of ceramic waste (CW) from different countries (Argentine and Czech Republic) are investigated. The mini slump, the heat released rate up to 48 h, the pozzolanic activity and the compressive strength at 2, 7 and 28 are determined. Hydration process is characterized by XRD analysis and the pore size refinement is accessed by MIP. Results show that both CWs increase the water demand with increasing the cement replacement level, and they possess pozzolanic activity after 7 days. At early age, the heat released and the compressive strength are lower than that of the Portland cement (PC) for all replacement levels. At 28 days, the pozzolanic reaction significantly improves the compressive strength. From XRD analysis, it is evident that CW reacts to form AFm phases (hemicarboaluminate at 7-28 and later transformed to monocarboaluminate) depending on the replacement level and CW used. CH peak reduction due to the pozzolanic reaction appears at 28 days. The reduction of porosity up to 16-24 % of CW replacement is in accordance with the compressive strength results.

Characterization of Cement Pastes Containing Natural Zeolite as a Pozzolanic Admixture

A possible use of natural zeolite originating from a mining area in South Slovakia as a pozzolanic material suitable for the partial cement replacement in composite production is studied. Measurement of chemical composition of natural zeolite is performed using XRF analysis. The particle size distribution of zeolite and dry paste mixtures is accessed on laser diffraction principle. For the tested pastes, basic physical properties and mechanical properties are determined. The obtained results indicate a good potential for the application of natural zeolite in the composite mix design.

Hydration of blended cement pastes containing waste ceramic powder as a function of age

The production of a cement binder generates a high amount of CO2 and has high energy consumption, resulting in a very adverse impact on the environment. Therefore, use of pozzolana active materials in the concrete production leads to a decrease of the consumption of cement binder and costs, especially when some type of industrial waste is used. In this paper, the hydration of blended cement pastes containing waste ceramic powder from the Czech Republic and Portland cement produced in Argentina is studied. A cement binder is partially replaced by 8 and 40 mass% of a ceramic powder. These materials are compared with an ordinary cement paste. All mixtures are prepared with a water/cement ratio of 0.5. Thermal characterization of the hydrated blended pastes is carried out in the time period from 2 to 360 days. Simultaneous DSC/TG analysis is performed in the temperature range from 25 °C to 1000 °C in an argon atmosphere. Using this thermal analysis, we identify the temperature, enthalpy and mass changes relat...

Fine Ceramic Powder – Supplementary Cementitious Material for Mortar Mix Design

Waste ceramic powder originating from the contemporary hollow bricks production is studied as a supplementary cementitious material in mortar composition. For the ceramic powder and cement, the measurement of chemical composition is done using XRF analysis. XRD device is used for the amorphous phase content measurement. The particle size distribution of ceramics and cement is accessed on a laser diffraction principle. Pozzolanic activity of ceramic powder was determined by the modified Chapelle test. The blended binder containing ceramic powder in an amount of 8, 16, and 24% of mass of cement is used for the preparation of mortars which are then characterized using the measurement of basic physical properties and mechanical properties. Among the basic physical properties, bulk density, matrix density and total open porosity are measured. The mechanical resistivity of mortars with blended binder is accessed by the compressive strength, flexural strength, and dynamic Young’s modulus measurement. Additionally, pore-size distribution of the developed mortars is analyzed using mercury intrusion porosimetry. Experimental data shows that an application of 24% waste ceramics in the blended binder provides sufficient mechanical resistivity of the mortar.

Study of Mass Changes of Cement Pastes as a Function of Age Using Thermogravimetry

We study the hydration and pozzolanic reactions of cement pastes made from Portland cement (CEM I 32.5 R) from the Czech Republic as a function of age, using thermogravimetry. The measurements are done for 2, 7, 28, 90, and 180 days cured samples in order to monitor the rate of hydration. The investigation is performed in the temperature range from 25 °C to 1000 °C with a heating rate 5 °C/min in an argon atmosphere. The mass change during the decomposition of calcium silicate hydrate gels, portlandite, and calcite are determined, and the changes in the portlandite amount are estimated in dependence on the time of hydration.

Ceramic Waste Powder as an Active Pozzolanic Material for Cement Based Composites

Parameters of cement pastes with ceramic powder as partial Portland cement replacement up to 40 mass% are presented in the paper. Ceramic powder belongs to the pozzolanic materials. Utilization of pozzolanic materials is accompanied by lower request on energy needed for Portland clinker calcination which generally results in lower production costs of blended binder and lower CO2 emissions. The ceramic powder is used in cement based pastes composition in amount of 8, 16, 24, 32, and 40 mass% of cement. For the studied ceramic powder, chemical composition is measured by X-Ray Fluorescence. The particle size distribution of ceramics is accessed on laser diffraction principle. Bulk density, matrix density, and total open porosity are measured for 28 days cured paste samples. The obtained results demonstrate that ceramic powder has potential to replace a part of Portland cement in composition of cement based composites.