The Utilization of a Combination of Recycled Rubber from Waste Tires and Waste Waters from a Concrete Plant in the Production of Cement Composites

2020 ◽  
Vol 838 ◽  
pp. 59-66
Author(s):  
Jakub Svoboda ◽  
Vojtěch Václavík ◽  
Tomáš Dvorský ◽  
Lukáš Klus ◽  
Jiří Botula

This article presents the results of a study dealing with the use of a combination of recycled rubber from waste tires as a 100% replacement of aggregate and waste sludge water from a concrete plant as a partial replacement of mixing water in the production of cement composites. The aggregate was replaced with recycled rubber material in two ratios. The first ratio was 50/50 and the other one was a 40/60 ratio of fraction 0/1 mm and fraction 1/3 mm. The mixing water was replaced with waste sludge water from a concrete plant in the amounts of 25% and 50%. The designed cement composite formulas were subjected to the test of their physical and mechanical characteristics in order to determine the properties when using a combination of recycled rubber and waste sludge water from a concrete plant. The tested properties include: consistency of the grain curve, mixing water properties, consistency of cement mortar, strength characteristics (tensile flexural strength and compressive strength). The study presents the results that are fundamentally different from the comparative samples and their use in the building industry but, at the same time, they also open up new possibilities of their use as building material.

2021 ◽  
Vol 11 (6) ◽  
pp. 2725
Author(s):  
Jakub Svoboda ◽  
Tomáš Dvorský ◽  
Vojtěch Václavík ◽  
Jakub Charvát ◽  
Kateřina Máčalová ◽  
...  

This article describes an experimental study aimed at investigating the potential use of recycled rubber granulate from waste tires of fractions 0/1 and 1/3 mm in cement composites as a 100% replacement for natural aggregates. The use of waste in the development and production of new building materials represents an important aspect for the sustainability and protection of the environment. This article is focused on the sound-absorbing and thermal-insulating properties of experimental cement composites based on recycled rubber from waste tires. The article describes the grain characteristics of recycled rubber, sound absorption capacity, thermal conductivity and strength characteristics. The results of this research show that the total replacement of natural aggregate with recycled rubber in cement composites is possible. Replacing natural aggregate with recycled rubber has significantly improved the thermal and acoustic properties of the prepared cement composites, however, at the same time; there was also the expected decrease in the strength characteristics due to the elasticity of rubber.


2019 ◽  
Vol 9 (21) ◽  
pp. 4519
Author(s):  
Klus ◽  
Václavík ◽  
Dvorský ◽  
Svoboda ◽  
Botula

This paper presents the results of research dealing with the use of recycled waste sludge water from a concrete plant (CP) as partial or complete replacement of mixing water in cement mixtures. The need to recycle waste sludge water generated as a by-product (waste sludge water) during the production of fresh concrete in the concrete plant results from the environmental and economic problems associated with the operation of the concrete plant. Mixing water was replaced with recycled waste sludge water in the amount of 25%, 50%, 75%, and 100%. In order to determine the effect of partial or complete replacement of mixing water with waste sludge water from the concrete plant in the production of cement composites, laboratory tests of waste sludge water were carried out to determine whether the waste sludge water complies with the requirements for mixing water defined in CSN EN 1008. The tests also determined the properties of fresh cement mortar and hardened cement composites. These were tests of the beginning and end of cement mortar setting, and the strength characteristics (flexural strength, compressive strength). The results of these tests show that it is possible to replace the mixing water by waste sludge water from the concrete plant in the amount of up to 25% without significantly affecting the tested properties, in comparison with the formula containing pure mixing water.


2020 ◽  
Vol 66 (1) ◽  
pp. 33-39
Author(s):  
Jakub Jakub ◽  
Vojtěch VÁCLAVÍK ◽  
Tomáš DVORSKÝ ◽  
Kateřina MÁČALOVÁ ◽  
Jakub CHARVÁT ◽  
...  

2019 ◽  
Vol 14 (1) ◽  
pp. 39-46
Author(s):  
Lukas Klus ◽  
Jakub Svoboda ◽  
Vojtech Václavik ◽  
Tomas Dvorský ◽  
Jiri Botula

Abstract This article presents the results of a research dealing with the effect of CO2 on cement composites prepared on the basis of waste sludge water from the concrete plant. The designed formulas R1 and R3 use waste sludge water from the concrete plant as a partial or complete replacement of mixing water in the production of cement composites. The mixing water was replaced by waste sludge water in the amounts of 25%, 50%, 75% and 100%. Laboratory tests that are defined in ČSN EN 1008 standard were performed in order to determine the effect of partial or complete replacement of mixing water. The test specimens were further subjected to the effect of CO2 in the Lamart laboratory chamber, where the effect of CO2 was simulated for the period 50 years. Subsequently, the cement composites were tested for their strength characteristics (tensile flexural strength, compressive strength) and subjected to a mineralogical analysis. The results show that the effect of CO2 will reduce the strength characteristics of the composite compared to the comparative samples.


2017 ◽  
Vol 68 (10) ◽  
pp. 2367-2372 ◽  
Author(s):  
Ng Hooi Jun ◽  
Mirabela Georgiana Minciuna ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Tan Soo Jin ◽  
Andrei Victor Sandu ◽  
...  

Manufacturing of Portland cement consists of high volume of natural aggregates which depleted rapidly in today construction field. New substitutable material such as bottom ash replace and target for comparable properties with hydraulic or pozzolanic properties as Portland cement. This study investigates the replacement of different sizes of bottom ash into Portland cement by reducing the content of Portland cement and examined the mechanism between bottom ash (BA) and Portland cement. A cement composite developed by 10% replacement with 1, 7, 14, and 28 days of curing and exhibited excellent mechanical strength on day 28 (34.23 MPa) with 63 mm BA. The porous structure of BA results in lower density as the fineness particles size contains high specific surface area and consume high quantity of water. The morphology, mineralogical, and ternary phase analysis showed that pozzolanic reaction of bottom ash does not alter but complements and integrates the cement hydration process which facilitate effectively the potential of bottom ash to act as construction material.


Vestnik MGSU ◽  
2016 ◽  
pp. 72-81
Author(s):  
Roman Sergeevich Fedyuk

The paper deals with the development of composite binders for producing concrete with improved characteristics of gas, water and vapor permeability. The authors investigate the processes of composite materials formation in order of decreasing scale levels from macro to nanostructures. The criteria for optimization of the volume of dispersed additives in concrete are offered. The authors theoretically studied the technological features of the formation of hydrated cement stone structure. A positive effect of nanodispersed additives on the structure and physico-mechanical properties of cement composite materials are predicted. Thanks to its improved features, such as good ratio of strength and body density, high density and lifetime, the modified concrete may be used when solving various practical tasks of the construction branch.


Vestnik MGSU ◽  
2020 ◽  
pp. 1523-1533
Author(s):  
Vladimir T. Erofeev ◽  
Victor V. Afonin ◽  
Tatiana F. Elchishcheva ◽  
Marina M. Zotkina ◽  
Irina V. Erofeeva

Introduction. An engineering method is proposed for assessing salt formation on the surface of cement composites exposed to adverse operating conditions. The technique is based on the histogram method used to determine the dominant brightness of the half-tone image of scanned cement composites. The criterion for ranking composites is a relative dimensionless value –– a metric obtained by comparing the brightness of a grayscale image with the brightness level of white. Materials and methods. We selected three types of compositions of composites in the amount of 21 items; each of them contains three samples –– a control sample and samples exposed to high humidity and positive temperatures for 15 and 45 days. Each composition is represented by a scanned raster image of the sample surface. The images are further subjected to digital processing using a software program written in the C++ programming language and the OpenCV technical vision library. This allows you to use the available methods and classes to develop algorithms to solve the problem in question and to convert a full-color RGB image to a grayscale image. Such images are used to analyze histograms, which determine the dominant level of brightness to determine the numerical metric for quantifying the salt formation on the surface of cement composite samples on the basis of their scanned images. Results. A description of the software algorithm, used to detect salt formation on the surface of cement composite specimens that have passed performance tests under high humidity conditions at positive temperatures, is presented. The method of ranking cement composite samples using the values of their dominant brightness relative to the brightness of control samples is shown. The comparative analysis of the study is presented in the form of numerical data and explanatory diagrams. Conclusions. Software modeling is employed to demonstrate the expediency of the methodology for the assessment of salt formation on the surface of cement composites and other building materials prone to salt formation.


Author(s):  
Genadijs Sahmenko ◽  
Sandis Aispurs ◽  
Aleksandrs Korjakins

Traditionally, sculptural and decorative elements of building facades are created from mortar mixes based on lime, gypsum or Portland cement. Generally these materials have porous and permeable structure, which determines their accelerated degradation, especially in the aggressive environment of modern cities. High performance cement composites (HPCC) have been considered for production and restoration of sculptural elements in historical buildings. For this purpose, fine-graded, multi-component and highly workable mixes were elaborated. Mix compositions were modified with micro-fillers, plasticizing and stabilizing admixtures, as well as fibers to improve material ductility and control shrinkage cracking. Basic mechanical properties and durability (such as water absorption, frost resistance) were determined and two types of HPCC were compared (>50 MPa: HPCC and >120 MPa: UHPCC). It has been confirmed that cement composite mixes are characterized by self-consolidating effect, high compressive strength, extremely high resistance versus freezing and thawing cycles and low water absorption. Surface quality was evaluated and initial water absorption (tube tests) were performed for laboratory samples and real sculptural elements after 5 years of exploitation. The results confirmed good potential for using HPCC for creating more attractive and durable architectural shapes and façade elements compared to elements made using traditional cement and lime mortar.


2000 ◽  
Vol 27 (3) ◽  
pp. 543-552 ◽  
Author(s):  
Yixin Shao ◽  
Shylesh Moras ◽  
Nilgun Ulkem ◽  
George Kubes

Wood fibres derived from both hardwood and softwood, being relatively inexpensive and in ample supply, have gained increasing popularity in the fibre-cement building product industry. Presently, the manufacture of most wood fibre - cement composites employs the Hatschek process. The purpose of this paper is to examine the feasibility of using extrusion technology for the production. Wood fibre - cement sheets, composed of both hardwood and softwood fibres of different fibre contents, were fabricated using an auger-type extruder. The flexural behavior, moisture content, water absorption, and density of all batches were evaluated. To investigate the weathering durability of the extruded composites, materials were also subjected to a temperature-cycling test and a natural exposure weathering test. With a relative ease of manufacture and a much cleaner production, extrusion was found to be a suitable means for making cement composite thin sheets with up to 8% fibres by weight. The extruded composites exhibited a performance comparable to or even better than that of the Hatschek products. Hardwood fibres, which are cheaper and more available than the softwood fibres, were found to be more suitable for extrusion production in terms of the extrudability, finished surface, and long-term mechanical properties.Key words: wood fibre - cement composites, hardwood pulp, softwood pulp, extrusion, strength, toughness index, temperature cycling, natural weathering.


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