The application of natural zeolite to cement concrete intended for communications surfaces

The article presents the application of a cement substitute in the form of natural zeolite to cement concrete. The reference mix design intended for communications surfaces and a mix of modified composition taking into consideration zeolite content were prepared. The basic parameters of concrete mix components were specified, including basalt aggregate, cement and zeolite. The influence of the applied zeolite of a grain-size distribution up to 50μm on the obtained parameters of concrete mix and hardened concrete was determined. It was observed that the applied zeolite contributes to the modification of the internal structure of concrete composite and consequently to the increase of the mechanical and physical parameters of hardened concrete tested within diversified standard periods of time. Due to the fact that the resistance of concrete to cyclic freezing and thawing is the determinant of concrete durability, in the case of pavement structure, hardened concretes were subject to a frost resistance assessment. The influence of zeolite content on both internal and external frost resistance of hardened concrete was specified. SEM observations of the internal structure of concretes exposed to the influence of freezingthawing cycles proved the advantageous changes of zeolite occurrence in concrete mix. A reduction of cement quantity and its replacement thereof with the suggested zeolite allows obtaining a pavement quality concrete of a more favourable internal micro structure and distinguished by higher parameters

The Influence of the Aircraft Operating Fluids on the Mechanical Parameters of the Airport Surface Concrete

The authors of the article assessed the impact of operating fluids used to service aircraft on changing mechanical parameters of cement concrete intended for airport pavement. The research concerned concrete designed with the use of CEM I 42.5N LH NA low-alkali cement, broken granite aggregate, fine washed aggregate, and admixtures. The analysis included the assessment of changes in differences in endurance parameters over various research periods of up to 140 days. The obtained results allowed to carry out statistical analysis using the student’s T-test. Research has shown a significant impact of operational fluids used in aircraft on the surface concrete properties of the airport. A reduction in the compressive strength of concrete exposed to one of the tested operating liquid to a reduction of 7.2% was observed over a period of 140 days, while there was no significant impact of operating fluids on tensile strength at splitting

Usefulness of porphyry and amphibolites as a component of concrete for airfield pavements

Coarse aggregate used as part of cement concrete is of primary significance for the obtained parameters of hardened concrete. In case of concretes intended for airfield pavements, the application of granite grit is recommended. Alternative to this type of aggregate in the form of porphyry and amphibolites aggregate was suggested. In order to assess the suitability of different aggregate types for concrete mixes, their bulk density, absorbability, polishing resistance, abrasion and crushing resistance were determined. Also, the internal structure of the suggested aggregates and its influence on changes of hardened concrete composite structure were subject to the assessment. The influence of aggregate type on the structure of cement matrix and contact areas between the matrix and aggregate grains were specified. The observed changes, in case of the internal structure of concretes based on porphyry and amphibolites aggregates, with reference to granite aggregate, resulted in changes of mechanical and physical parameters. Analyses included the determination of bulk density, absorbability, compression, bending and splitting resistance. According to the obtained laboratory test results, the significant influence of the aggregate type applied to the mix on parameters of hardened concrete, with regard to the application thereof to the airfield pavements was proved

Influence of Operating Media on the Parameters of Cement Concrete Intended for Airfield Pavements

The article presents the influence of the suggested operating media on the modification of parameters of cement concrete intended for airfield pavements. Cement concrete contains cement CEM I 42,5, granite grit, fine washed aggregate, water and air entraining as well as plasticizing additive. Analyses included the assessment of changes in mechanical and physical parameters (weight absorbability and water capillary action) of hardened concrete. The observed changes were associated with the internal structure of concrete composite. Based on the obtained results, different influence of the applied operating media on mechanical parameters of hardened concrete was determined

Usefulness of porphyry and amphibolites as a component of concrete for airfield pavements

Coarse aggregate used as part of cement concrete is of primary significance for the obtained parameters of hardened concrete. In case of concretes intended for airfield pavements, the application of granite grit is recommended. Alternative to this type of aggregate in the form of porphyry and amphibolites aggregate was suggested. In order to assess the suitability of different aggregate types for concrete mixes, their bulk density, absorbability, polishing resistance, abrasion and crushing resistance were determined. Also, the internal structure of the suggested aggregates and its influence on changes of hardened concrete composite structure were subject to the assessment. The influence of aggregate type on the structure of cement matrix and contact areas between the matrix and aggregate grains were specified. The observed changes, in case of the internal structure of concretes based on porphyry and amphibolites aggregates, with reference to granite aggregate, resulted in changes of mechanical and physical parameters. Analyses included the determination of bulk density, absorbability, compression, bending and splitting resistance. According to the obtained laboratory test results, the significant influence of the aggregate type applied to the mix on parameters of hardened concrete, with regard to the application thereof to the airfield pavements was proved

Testing the Influence of Metakaolinite and Zeolite on the Adhesion of BFRP and GFRP Bars to Concrete

Today’s sustainable development policy in Europe, which is driven by concerns about the greenhouse effect and environmental protection, mandates a reduction in CO2 emissions into the atmosphere. The cement industry and steel mills that produce reinforcing bars are among the largest and most emissions-intensive sectors emitting CO2 into the atmosphere. This article analyzes the possibility of achieving significant reductions in CO2 emissions by using basalt bars (BFRP) and glass bars (GFRP) in concrete structures, and—in the case of concrete—by using cement with the addition of metakaolinite and zeolite. There is a lack of literature reports on whether modifying concrete with the additions of metakaolinite and zeolite as substitutes for part of the cement affects the adhesion of FRP bars to concrete. It can be assumed, however, that improving the microstructure of concrete also improves the contact zone between the bar and the concrete. The aim of this research is to fill the aforementioned gap in the literature data by determining how the presence of metakaolinite and zeolite affects the adhesion of reinforcing bars to concrete and testing selected properties of hardened concrete. The test samples were prepared following the appropriate beam test procedure. The obtained results made it possible to perform a comparative analysis of reference samples and those with metakaolinite and zeolite additions. The research showed that introducing active pozzolanic additives in the form of metakaolinite and zeolite into concrete improved adhesion stress values by approximately 20% for glass GFRP bars and 15% for basalt BFRP bars, especially in the destruction phase