Recycled Rubber in Cement Composites

1994 ◽  
Vol 344 ◽  
Author(s):  
D. Raghavan ◽  
K. Tratt ◽  
R. P. Wool
Keyword(s):  
Cement Paste ◽  
Rubber Particle ◽  
Cement Composite ◽  
Peel Strength ◽  
Innovative Technology ◽  
Cement Matrix ◽  
Strength Analysis ◽  
The Us ◽  
Rubber Cement ◽  
Environmentally Sound

AbstractDisposal of 200 million waste tires in the US each year has become a major problem. An environmentally sound innovative technology of recycling rubber in cement matrix was examined. Using silane coupling agent the rubber was bonded to the hydrating cement making a lighter composite, which absorbed more energy than ordinary Portland cement. The bonding information was obtained by peel strength analysis. SEM was used to understand the mode of fracture in pure cement paste, cement bonded rubber composite and rubber filled cement paste. It was found that cracks propagate through the rubber particle in rubber bonded cement composite while in unbonded rubber cement mix, the cracks propagate around the interface. The density and shrinkage measurements are also discussed.

scholarly journals Damping Property of a Cement-Based Material Containing Carbon Nanotube

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Wei-Wen Li ◽  
Wei-Ming Ji ◽  
Yi Liu ◽  
Feng Xing ◽  
Yu-Kai Liu
Keyword(s):  
Carbon Nanotube ◽  
Cement Paste ◽  
Load Transfer ◽  
Cement Composite ◽  
Mechanical Analysis ◽  
Cement Matrix ◽  
Cement Composites ◽  
Strength Index ◽  
Damping Property ◽  
Reduction Capacity

This study aimed to explore the damping property of a cement-based material with carbon nanotube (CNT). In the study, the cement composites with different contents of CNT (0 wt%, 0.033 wt%, 0.066 wt%, and 0.1 wt%) were investigated. Logarithmic Decrement method and Dynamic Mechanical Analysis (DMA) method were utilized to study the damping property of CNT/cement composite. The influences of CNT on pore size distribution and microstructure of composite were analyzed by Mercury Intrusion Porosimetry (MIP) and Scanning Electron Microscopy (SEM), respectively. The experimental results showed that CNT/cement composite presented higher flexural strength index than that of a pure cement paste. Additional CNT could improve the vibration-reduction capacity of cement paste. Furthermore, the experiments proved that CNT could bridge adjacent hydration products and support load transfer within cement matrix, which contributed to the energy dissipation during the loading process.

Microstructural Study of Cement Composites Produced by Hazardous Waste Stabilization/Solidification

2012 ◽  
Vol 587 ◽  
pp. 97-101
Author(s):  
Bozena Vacenovska ◽  
Rostislav Drochytka ◽  
Vit Cerný
Keyword(s):  
Fly Ash ◽  
Hazardous Waste ◽  
Cement Composite ◽  
Cement Matrix ◽  
Main Task ◽  
Cement Composites ◽  
Microstructural Study ◽  
Waste Stabilization ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

This paper deals with the chosen hazardous waste solidification/stabilisation (S/S) under the catalogue code 190811 using cement matrix with addition of classic fly ash and fluid fly ash as secondary raw binders. The main task of the research works was a microstructural study of the most successful S/S formula that will be used for development of new reclamation material. The S/S process product was subject to X-Ray analysis and to the electron microscopy analysis two years after its production to evaluate the possibility of degradation of the cement composite and releasing the contaminants into environment.

Einfluss der elektrochemischen Doppelschicht auf die Sorption und den Transport von Chlorionen im Zementstein / Influence of the electrochemical double layer on sorption and transport of chlorides in hardened cement paste

2000 ◽  
Vol 6 (4) ◽  
pp. 415-428
Author(s):  
O. Wowra ◽  
M.J. Setzer
Keyword(s):  
Double Layer ◽  
Cement Paste ◽  
Building Materials ◽  
Pore Solution ◽  
Chloride Ions ◽  
Transport Processes ◽  
Cement Matrix ◽  
Hardened Cement ◽  
Hardened Cement Paste ◽  
Electrochemical Double Layer

Abstract Besides the formation of Friedel salt the transport and binding of chlorides in concrete is mainly defined by the electrochemical double layer at the interface between cement matrix and pore solution. Due to the alkaline pore solution the surface of hardened cement paste is negatively charged which may change to positive values by the potential regulating calcium ions. Inverting of the surface charge leads to an attraction of anions and therefore, to an adsorption of chloride ions in the diffuse part of the electrochemical double layer. Influence from outside like sulphates and carbon dioxide may lead to a decomposition of Friedel salt. Apart from these effect temperature, pH-value and certain environmental conditions affects the electrochemical double layer as well. The chloride equilibrium is mainly controlled by adsorbed ions in the electrochemical double layer. The model presented here is relevant for the assessment of ion transport processes in mineral building materials. Continuing investigations may lead to optimize transport models and a better evaluation of the critical chloride threshold value in reinforced concrete.

Enhancement of Thermal and Sound Insulation Properties of Cement Composite Roofing Tile by Addition of Nanocellulose Coated Pineapple Fiber and Modified Rubber Tire Waste

2020 ◽  
Vol 861 ◽  
pp. 465-472
Author(s):  
Kanokon Hancharoen ◽  
Parames Kamhangrittirong ◽  
Pimsiree Suwanna
Keyword(s):  
Weight Ratio ◽  
Cement Composite ◽  
Sound Insulation ◽  
Type I ◽  
Cement Composites ◽  
Water To Cement Ratio ◽  
Rubber Particles ◽  
Reduction Coefficient ◽  
Rubber Cement ◽  
Better Than

In this work, the enhancement of thermal and sound insulation properties of cement composite roofing tile with nanocellulose coated pineapple fiber and modified waste tire rubber is studied. The composite was composed of bacterial nanocellose (BNC) coated pineapple fibers, modified rubber particles, platicizer and type I Portland cement in the weight ratio of 10:50:0.8:100 with the water to cement ratio (w/c) of 0.5. The thermal conducitity of the fiber rubber cement composite could be reduced to 0.1080 ± 0.0048 W/m.K as opposed to 0.3810 ± 0.0041 and 0.5860 ± 0.0050 W/m.K for the fiber cement and the rubber cement composites, respectively. Moreover, the noise reduction coefficient of the fiber rubber cement composite could be increased to 0.2832 as opposed to 0.2143 and 0.1899 for the fiber cement and the rubber cement composites, respectively. These results revealed that adding nanocellulose coated pineapple fiber and modified rubber particles together to the cement composite can enhance the thermal insulation and sound absorption abilities of the composite roof tile significantly better than adding each constituent separately.

scholarly journals Experimental Investigation of NaOH and KOH Mixture in SCBA-Based Geopolymer Cement Composite

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3437 ◽  
Author(s):  
Sardar Kashif Ur Rehman ◽  
Lahiba Imtiaz ◽  
Fahid Aslam ◽  
Muhammad Khizar Khan ◽  
Muhammad Haseeb ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Cement Paste ◽  
Cement Composite ◽  
Sem Analysis ◽  
Molar Ratio ◽  
Geopolymer Concrete ◽  
Concrete Durability ◽  
Geopolymer Cement ◽  
Ash Disposal ◽  
Durability Performance

This research aimed at exploring the effects of a mixture of sodium hydroxide (NaOH) and potassium hydroxide (KOH) activators in a sugar cane bagasse ash (SCBA)-based geopolymer cement paste. Bagasse ash replacement was 20% of cement by weight. The mixture of NaOH and KOH comprised 4, 8, and 12 M solutions with mixing percentages of 0%, 20%, 40%, 60%, 80%, and 100% for all possible combinations. A pH test was performed on each possible combination of solutions. A Chapelle’s test, XRD, X-ray fluorescence (XRF), and SEM analysis were used to check whether the SCBA exhibited pozzolanic reactivity. Subsequently, the SCBA geopolymer cement paste was tested for compressive strength, water absorption, permeable porosity, and sorptivity. It was estimated that the geopolymer cement paste exhibited higher absorption and sorptivity values than control mixtures when molarity increased. However, the samples prepared with combinations of the 8 M activator solution exhibited consistent absorption, sorptivity, and compressive strength values when compared to the control and other geopolymer mixtures with 4 and 12 M activator solutions. Thus, the two activator solutions G8N408K60 and G8N208K80—where GxNayKb represents the geopolymer concrete sample prepared by adding solutions of two bases, i.e., ‘xNayKb’ showing an ‘a’ percentage of ‘x’ molar NaOH and a ‘b’ percentage of ‘y’ molar KOH—were obtained as the optimum molar ratio of the activator in geopolymer concrete. The geopolymer cement pastes, along with the optimum and control samples, were further tested for concrete durability, SEM, and TGA tests. The G8N208K80 sample exhibited a better mechanical and durability performance than the G8N408K60 sample. The durability performance of the geopolymer concrete was also superior to ordinary concrete. Moreover, the geopolymer concrete achieved a 21% reduction in global warming potential compared to the control mixture. Thus, it can be concluded that the use of SCBA in geopolymer concrete can address the ash disposal and CO2 emission problems with enhanced durability.

scholarly journals Soil-concrete for use in the 3D printers in the construction of buildings and structures

2018 ◽  
Vol 245 ◽  
pp. 03002 ◽  
Author(s):  
Petr Iubin ◽  
Lubov Zakrevskaya
Keyword(s):  
Rheological Properties ◽  
Cement Paste ◽  
Clay Soil ◽  
Cement Composite ◽  
Cement Composites ◽  
Test Results ◽  
Flow Table ◽  
Key Factor ◽  
3D Printers ◽  
The Cost

Nowadays, the construction of cement composite using 3D printers is considered one of the most promising methods of automation of building processes. However, the compositions of cement composites have several disadvantages, such as high cost, short workability and etc. It has been suggested that clay soil as an additive will help to solve these problems partially. The aim of the work is development the cement compositions with clay soil, for use in 3D printers to construction. The composite consists of cement paste with clay soil and additives. To study printability of a composite the rheological properties in a fresh state were studied. The study of the rheological properties of composites was carried out using a flow table test for mortar. The key factor for determining the suitability of the composite for printing was accepted the diameter of the cone after shaking. The test results showed the possibility of replacing cement paste with clay soil up to 25% which leads to a reduction in the cost and an increase in printability with a slight decrease in the strength of the obtained material to 7%. Utilizing of soil from the construction site provides maximum economic efficiency of the material application.

scholarly journals Properties of Cracking Patterns of Multi-Walled Carbon Nanotube-Reinforced Cement Matrix

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2942 ◽  
Author(s):  
Maciej Szeląg
Keyword(s):  
Image Analysis ◽  
Cement Paste ◽  
Fractal Theory ◽  
Sodium Dodecyl ◽  
Crack Density ◽  
Surface Preparation ◽  
Cement Matrix ◽  
Multi Wall Carbon Nanotubes ◽  
Analysis Tools ◽  
Average Cluster

The research presented in this paper presents a quantitative analysis of cracking patterns on the surface of cement paste, which has been modified by the addition of the multi-wall carbon nanotubes (MWCNTs). The cracking patterns analyzed were created as a result of increased temperature load. MWCNTs were used as an aqueous dispersion in the presence of a surfactant, sodium dodecyl sulfate (SDS). Four series of the cement paste were tested, and the samples differed in the water/cement (w/c) ratio, cement class, and the presence of MWCNTs. Image analysis tools were used to quantify the cracking patterns and it was proposed to measure parameters, such as the average cluster area, average cluster perimeter, average crack width, and crack density. In order to facilitate the image analysis process, the sample surface was subjected to preparation and using statistical analysis tools it was assessed whether the method of surface preparation affects the way the sample is cracked. The paper also presents the analysis of the relationships that occur between parameters describing the cracking patterns, and also with the physico-mechanical properties of the cement pastes. It was attempted to explain the dependencies using elements of fractal theory and the theory of dispersion systems.

scholarly journals Thermal analysis of water confined in fully and partially saturated cement paste

2020 ◽  
Vol 172 ◽  
pp. 17008
Author(s):  
Dalia Bednarska ◽  
Marcin Koniorczyk
Keyword(s):  
Thermal Analysis ◽  
Cement Paste ◽  
Pore Solution ◽  
Cement Matrix ◽  
Complex Nature ◽  
Hardened Cement ◽  
Hardened Cement Paste ◽  
Scanning Calorimetry ◽  
Partially Saturated ◽  
Different Temperatures

The main object of the presented research is to apply thermal analysis in order to investigate microstructure of hardened cement paste. The test is conducted by means of differential scanning calorimetry on samples stored in various relative humidity levels as well as the fully saturated ones. The obtained results describe water solidification beginning at several different temperatures, which implies complex nature of cement paste microstructure. The recorded thermograms consist of two main peaks, which clearly indicate the division into capillary and gel pores. Additionally, the thermodynamic properties of actual pore solution confined in cement matrix are investigated. The obtained results indicate ions present in the liquid strongly affects its phase transition temperature as well as amount of ice formed during such the phase change.

scholarly journals Influence of Dispersing Method on the Quality of Nano-Admixtures Homogenization in Cement Matrix

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4865
Author(s):  
Elżbieta Horszczaruk ◽  
Paweł Łukowski ◽  
Cyprian Seul
Keyword(s):  
High Speed ◽  
Mechanical Performance ◽  
Chemical Properties ◽  
Cement Composite ◽  
Cement Matrix ◽  
Cement Composites ◽  
Nano Sio2 ◽  
Mechanical Stirring ◽  
Physico Chemical ◽  
Nano Fe3o4

In recent years, a nano-modification of the cement composites allowed to develop a number of new materials. The use of even small amount of nano-admixture makes possible not only to improve the physico-mechanical properties of the cement materials, but also to obtain the composite with high usability, optimised for the given application. The basic problem of nano-modification of the cement composites remains the effectiveness of dispersing the nanomaterials inside the cement matrix. This paper deals with the effect of the type and size of the nanoparticles on the tendency to their agglomeration in the cement matrix. The main techniques and methods of dispersing the nanomaterials are presented. It has been demonstrated, on the basis of the results of testing of three nanomodifiers of 0D type (nano-SiO2, nano-Fe3O4 and nano-Pb3O4), how the structure and properties of the nanomaterial affect the behaviour of the particles when dissolving in the mixing water and applying a superplasticiser. The nanoparticles had similar size of about 100 nm but different physico-chemical properties. The methods of dispersing covered the use of high-speed mechanical stirring and ultrasonication. The influence of the method of nano-modifier dispersing on the mechanical performance of the cement composite has been presented on the basis of the results of testing the cement mortars modified with 3% admixture of nano-SiO2.

Laboratory investigation of engineering properties of rubberized asphalt mixtures containing reclaimed asphalt pavement

2010 ◽  
Vol 37 (11) ◽  
pp. 1414-1422 ◽  
Author(s):  
Feipeng Xiao ◽  
Serji Amirkhanian ◽  
Bradley Putman ◽  
Junan Shen
Keyword(s):  
Resilient Modulus ◽  
Asphalt Pavement ◽  
Crumb Rubber ◽  
Asphalt Mixtures ◽  
Engineering Properties ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
The Us ◽  
Rubberized Asphalt Concrete ◽  
Environmentally Sound

An improved understanding of the rheological and engineering properties of a rubberized asphalt concrete (RAC) pavement that contains reclaimed asphalt pavement (RAP) is important to stimulating the use of these recycled and by-product materials in asphalt mixtures. The uses of RAP and rubberized asphalt in the past have proven to be economical, environmentally sound, and effective in hot mix asphalt (HMA) mixtures across the US and the world. The objective of this research was to investigate the binder and mixture performance characteristics of these modified asphalt mixtures through a series of laboratory tests to evaluate properties such as the fatigue factor G*sinδ, rutting resistance, resilient modulus, and fatigue life. The results of the experiments indicated that the use of RAP and crumb rubber in HMA can effectively improve the engineering properties of these mixes.

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