Hasanan Md Nor

Laboratory Performance of Crumb Rubber Concrete Block Pavement

The aim of this study was to investigate laboratory performance of crumb rubber concrete block pavement (CBP). Four different paving blocks containing 0 (control), 10, 20 and 30% rubber by total sand volume with compressive strength ranging between 23 and 64 MPa were used. The test pavement was subjected to 10,000 cycles of load repetition under a single truck wheel via a tyre inflated to 600 kPa. Nine measurements of pavement deformation and joint width were made at various stages of trafficking. Additional tests, including pull-out, skid resistances and falling weight test, were then carried out. Overall, crumb rubber CBP is observed to show inferior performance than the conventional CBP in rut, deformation, skid resistance and shear resistance but showed a great improvement in toughness. Thus, all paving blocks studied in this project have a great potential to be used according to traffic volume and types of applications.

Properties of crumb rubber concrete paving blocks with sbr latex

ABSTRACT The objective of this research is to investigate the potential of using crumb rubber as a partial substitute for coarse sand in the production of concrete paving block (CPB). Laboratory trials were conducted to investigate the effect of crumb rubber particle size. A comparison was also made between CPB mixtures containing various percentages of crumb rubber to determine the optimum crumb rubber content and water-cement (w/c) ratio. Styrene-butadiene rubber (SBR) latex was added to the mixtures of crumb rubber CPB and mechanical properties were evaluated. A total of 276 CPB were fabricated and tested in laboratory to determine the density, skid resistance and the compressive strength. The design strength level ranging from 31 to 43 MPa was achieved using w/c ratios of 0.45 to 0.55. The test results indicated that there was a systematic reduction in the strength with the increase in rubber content. Scanning electron micrograph showed that inclusion of SBR latex into the matrix did not improve the mechanical properties of the CPB. Results also revealed that a w/c ratio of as high as 0.55 without any SBR latex at 15% rubber content by total sand volume might be practically used to produce crumb rubber CPB which achieve the target compressive strength of 30 MPa.

Chemical properties of waste tyre rubber granules

This research aims to examine the chemical properties of waste rubber tyre granules. Rubber granules were analysed by using X-ray fluorescence to establish its chemical composition. Thermogravimetry and differential thermogravimetric analyses were performed to investigate the relationship between temperature and the minerological compositions of rubber granules to determine its suitability as an aggregate replacement in concrete mix. Fourier Transform Infra-Red (FTIR) indicated that due to the stability of the structures developed in OPC samples, the reactions between the structure bonds are less at the range of 650-1500 cm-1. Scanning electron microscopy (SEM) was performed to examine the physical properties of rubber granule particles and to magnify the bonds between cement and rubber granules in a concrete mix. The results of the SEM analysis showed that carbon, zinc, magnesium, and calcium are the major components of waste tyre rubber granules.

Mechanical properties of double layer rubberized concrete paving blocks

This paper sought to evaluate the influences of different levels of waste rubber tyre (rubber granules) as an aggregate replacement in the production of double layer concrete paving blocks (CPBs). Waste rubber tyres were used as an aggregate replacement at the levels of 0%, 10%, 20%, 30%, and 40%. The characteristics of the double layer rubberized CPB were examined via a series of tests. According to the results, the density, porosity, and compressive strength of the double layer rubberized CPB is highly influenced by the percentage of rubber content. The compressive strength test has proven that by using rubber granules as an aggregate, the compressive strength is able to be manipulated. As the percentage of rubber granules increase, the compressive strength will decrease as the amount of solid, load-carrying material reduces. Compressive strength was at its peak when the rubber content was at 10%. 1-4 mm rubber granules were used as a replacement of fine aggregate and 5-8 mm rubber granules as coarse aggregate; both at the level of 40%. As a result, a double layer rubberized CPB with 28-days compressive strength of maximum 28 MPa is produced.

Double Layer Concrete Paving Blocks Using Waste Tyre Rubber as Aggregate Replacement

This study provided the test results on the mechanical properties of double layer concrete paving blocks (CPBs) obtained by replacing portions of the conventional aggregate with waste tyre rubber. The mechanical properties discussed in this paper were compressive and flexural strength. Results indicated that the density of double layer CPBs containing rubber was lower than that of conventional CPB. The decrease was found to be proportional with the waste tyre rubber content. Due to the low strength and stiffness of waste tyre rubber particle, the compressive and flexural strength of double layer CPBs containing rubber appeared to be lower than that of conventional CPB.

Low Noise and Properties of Double Layer Concrete Paving Blocks

Double layer rubberized concrete block (DL-RCPB) was introduced to effectively make use of waste tyre and to improve the performance of concrete pavement block. This study was carried out to justify the effectiveness of using waste tyre rubber as aggregate. In this study, there were eight series of concrete mix with 10 and 20 % waste tyre rubber replacement level and different thickness of facing layer; 10, 20, 30 and 40 mm. The compressive strength was reduced when the percentage of waste tyre rubber was increased. Remarkably, all types of DL-RCPB with rubber percentage up to 20 % achieved minimum required compressive strength of 45 MPa. Moreover, DL-RCPB (20 %) with 40 mm top layer was proven to have the most effective sound absorption concrete mix design with up to 36 % of sound adsorption recorded. Reduction in block density was found when the percentages of rubber were increased. Porosity up to 17 % was recorded for DL-RCPB (20 %). The rough surface of rubber particles tends to attract air on the rubbers’ surface and the trapped air tends to produce voids once the concrete hardened. Porosity of DL-RCPB was increased when the rubber was added to concrete mix, thereby decreasing the density of DL-RCPBs. Low density and high porosity increased the intensity of sound absorption and relatively gives positive impact on the development of low noise CBP as long as the compressive strength was sufficient.

Effect of Rubber Tyre Granules on Concrete Strength and the Microstructure Characteristics of Rubberized Concrete

The influence of using rubber tyre granules (RTG) as aggregates on the strength of concrete and microstructure characteristics of rubberized concrete was investigated in this study. Mix proportion of cement: sand: aggregate: superplasticizer; 1:1.5:1.7:0.003 and 0.47 water cement ratio (w/c) was used. The RTG of size 1-4 mm and 5-8 mm were used throughout this study. Progressive reduction of strength was observed with the increased of RTG percentage and size. Thermogravimetry and differential thermogravimetric (TGA-DTA) analyses were performed to evaluate the decomposition process of materials heated up to 1000 oC. Less reactions the structure bonds are less at the range of 2000-3000 cm-1 wavelength were detected in Fourier Transform Infra-Red (FTIR) analysis due to the stability of the structures developed in concrete samples. In general, the main elements were calcium, carbon, silica and aluminum. The existence of SBR and carbon black of RTG in the sample can be observed by the presents of a carbon peak in EDX.