Advanced Materials Research Vol. 897

Abstract: The paper is concerned with assessment of blended cement high proportion in mix design of concrete. A long term development of concrete compressive strength and static modulus of elasticity were monitored. The cement proportion reached even 450 kg per m³ of concrete. The high proportion of blended cement was used with aim to obtain declared modulus of elasticity values for the given concrete strength class according to EN 1992-1-1. And just the blended cement influence was positively verified in the long-term development of both monitored parameters.

Abstract: Sprayed concrete is widely applied in spite of developing economical crisis. The paper focuses on possibilities of manufacture and testing basic physical parameters of sprayed concrete prepared in common laboratory mixer and compacted by vibration combined with defined level of pressure. The aim is assessment of basic properties of sprayed concrete: compressive strength of early age sprayed concrete, strength of drilled core, assessment of homogeneity and density of concrete, determination of elasticity modules. On the basis of results, possible correlation relationships will be predicted for this manufacture process and for common application by means of spraying onto a structure.

Abstract: The present paper deals with the use of Impact-echo acoustic method to test cement-based mortar composites degraded at high temperatures. The specimens were prepared by using a type CEM I Portland cement and siliceous sand, as well as by substituting 25% of sand with shredded automobile tires and by adding acrylic polymer binder (20% w/w to cement mass). The samples were were subjected to high-temperature treatment in the temperature range of 200-400 °C. The acoustic results confirmed the differences in the structure of mortar specimens. The addition of rubber aggregates in H2 and H3 specimens resulted in lower frequencies compared to H1 specimen. It was also observed the dropping down of the frequencies for the temperatures between 200-300°C, indicating that the effect of heat treatment was mitigated when the acrylic binder was added.

Abstract: The aim of the work was to use common waste glass materials as fillers in polymer resin and to propose the use it for selected multilayer polymer flooring systems which belongs to widespread materials for industrial and also public constructions. Authors decided to use polymer binder based on two different 2-component commercial epoxides Lena N 102 and Lena N 128. Common available secondary materials which replaced original filler were tested in mentioned polymer binder. Tested glass fillers were chosen according its chemical composition and physical properties. Used recycled materials were glass of windscreen, glass beads, screen, glass packaging and fluorescent glass. The filler compatibility with binder matrix was determined according mixture processability, applicability and evaluation of hardened surface.

Abstract: This paper presents some test-results of using fine recycled concrete as a partial replacement of natural aggregates in cement-based flowscreed. Special attention is given to describing and studying rheological characteristics and mechanical properties of cement-based flowscreed. Experimental results indicate that it is possible to prepare flowscreed with partial replacement of natural aggregates by recycled aggregates and obtain a quality that meets the requirements. This study was partially connected to the research-project RecyFlowscreed [1].

Abstract: The aim of this research realized within the scope of this paper was to select the most proper representative from the chosen number of waste industrial sludge for solidification technology with use of cementation process. This chosen representative of waste industrial sludge will be further subjected to the detailed laboratory testing of its solidification possibilities in the term of its future use in building industry.

Abstract: This contribution deals with the issue of epoxy resin based sealing layers as a part of waterproofing system of concrete bridge decks. The contribution focuses on semi-operational and laboratory tests performed to investigate failures of the carriageways on bridges.

Abstract: The aim of the work was to propose the application for waste secondary materials as filler in polymer coating systems. Authors decided to use two different water-based epoxide binders: Lena N141 and Lena N 121 and the waste suitable materials were chosen by its chemical and physical composition and properties. Used recycled materials were glass of windscreen, glass beads, screen, glass packaging and fluorescent glass. The particle size and scanning of grain were determined. The chemical resistance and the adhesion of coating materials to the common substrate were also tested. The chemical resistance was tested with substances: distilled water, oil, petrol, acetone, 20% water solution of NaCl, 50 % water solution of ethanol, 5 % and 30 % water solution of NaOH a 20 % water solution of H₂SO₄.

Abstract: The influence of vacuum mixing on the porosity of ultra-high performance concrete (UHPC) was examined. For this reason, test specimen with a typical mix composition for UHPC were prepared and cured in six different ways. The pore size distribution and the total porosity were determined by the use of mercury intrusion porosimetry (MIP). The results show that the total porosity of vacuum mixed UHPC is significantly different than of conventionally mixed UHPC within all curing methods. Since UHPC generally only has a little amount of capillary pores, a change in porosity was determined due to a change in the range of gel pores.

Abstract: Locks are highly stressed massive concrete structures. Depending on the location and function of the specific component, different demands regarding temperature development, workability, compressive strength and durability of the building materials have to be fulfilled. Particularly the design and the production of the chamber wall concrete with a high frost resistance and strict limitations of the development of the heat of hydration represents a concrete technological challenge. In this paper the experiences gained in the development, production and placing of the concretes of a lock in Northern Germany are compiled.