Papers by Keyword: Plastic Concrete

Abstract: In developing countries, the management of waste continues to be a major challenge, especially in urban areas. One of the major concerns for today’s world is the management of plastic and construction and demolition (C&D) wastes which are increasing with urbanization and population growth. This study aims to explore the possibility of the use of plastic waste as a binder and recycled aggregates obtained from C&D waste to produce concrete paving blocks. The mechanical investigation was carried out to find the optimum content of plastic waste to prepare the plastic concrete. Three different concrete mixes were prepared with plastic contents of 30%, 40%, and 50% by the weight of aggregate. To evaluate the mechanical properties of plastic concrete, compression, flexural, and ultrasonic pulse velocity (UPV) tests were performed on the prepared samples. Cubical specimens of 36 x 40 x 40 mm for compression tests and prismatic specimens of 36 x 40 x 120 mm for flexural tests were cut using a saw from the paving blocks of size 36 x 137 x 290 mm. The results indicated that the strength of plastic concrete increased with the increase in plastic content. The maximum compressive and flexural strength was achieved at 50% plastic content, which was 40.52 MPa and 10.13 MPa, respectively. The compressive and flexural strengths of plastic concrete were compared with the minimum strength requirement specified by various standards specification such as American, Canadian, and Chinese. It was found that plastic concrete with 50% content of plastic waste meets the minimum criteria of mechanical strengths specified in these standards. Presently, many countries of the African continent are facing severe problems of plastic waste. As per the findings of this study, the use of waste plastics in molten form as the only binder in the development of concrete paving blocks could offer a solution for such countries to beneficially manage the plastic waste.

Abstract: By numerical calculation, it analyzed the seepage effects of plastic concrete cut-off wall in in construction period. On construction period, the seepage flow from inside of channel to outside at unit length is 0.753m³/h. The seepage flow from under plastic concrete cut-off wall is 0.646m³/h which is 85.79% of total seepage flow. Under certain condition on operation period, the seepage flow from inside of channel to outside at unit length is 0.394m³/h. The seepage flow from under plastic concrete cut-off wall is 0.358m³/h which is 90.86% of total seepage flow. Under another condition on operation period, the seepage flow from inside of channel to outside at unit length is 0.249m³/h. The seepage flow from under plastic concrete cut-off wall is 0.236m³/h which is 94.78% of total seepage flow. In It showed the plastic concrete cut-off wall has obvious effect.

Abstract: This test is sand coarse aggregate ratio, ratio of water to cementitious material, cement dosage, bentonite dosage, type of sand and type of bentonite in certain cases, studied the influence of clay dosage and curing age on the basic mechanical properties of plastic concrete, it is concluded that the best clay dosage; the clay dosage has a great influence on all the strength of plastic concrete (compressive strength, splitting tensile strength, rupture strength), with the increase of clay dosage and all kinds of strength decreased; when clay dosage is certain, various strengths of plastic concrete are increased with the increase of curing age, curing age has a great influence on various strengths of plastic concrete. If the long curing age (540d) intensity values as the actual strength of plastic concrete, growth rate of strength of 540d long age relative to the 28d age about 120%, this shows that plastic concrete has a higher late strength, plastic concrete curing age longer than concrete curing age.

Abstract: A displacement sensor was designed and made for the deformation modulus test of plastic concrete according to the method of full gauge measurement. Such parameters as sensitivity, linearity and repeatability, etc. were obtained after the calibration of the sensor. The results show that the indicators have met the requirements on the class-1 precision. The results from the practical application of engineering test indicate that the designed displacement sensor which is easy to use and high in the degree of precision can meet the needs of practical application of engineering.

Abstract: Through laboratory testing, the main properties and effects of rubber particle and water-binder ratio of plastic concrete are researched. The results indicate if the rubber particle of plastic concrete with certain water-binder ratio increases and its elastic modulus decreases, there is no effect to the permeability coefficient of plastic concrete basically. If the water-binder ratio of plastic concrete is lower, its elastic modulus increases but permeability coefficient reduces distinctly. Therefore, the comprehensive utilization of the test of rubber particle with change of water-binder ratio can make up plastic concrete with lower elastic modulus and smaller permeability coefficient. It will provide a new method to solve the problem of plastic concrete with higher elastic modulus and larger permeability coefficient and meet the needs of a project.

Abstract: Plastic concrete is a composite material between the normal concrete and clay, with its characteristics of long curing age and slowed growth of strength. In this paper, the mathematical models of relationship between compressive strength (curing age of 540 days) and curing age (28 and 90 days) are established on the basis of multitudinous of tests. Comparing the value obtained by calculating model with experimental value, we find that they have well consistency. The establishment of these models provide the basis for making plastic concrete standard procedures and carrying out numerical analysis, and they also offer reference for engineering application of plastic concrete.

Abstract: This article carried out the strength experiments on four hundred and five specimens with twelve mix proportions and three curing ages, systematically investigated the relationships of related strengths, the dimensional effect of compressive strength and splitting tensile strength of plastic concrete. The results showed that there well exist the statistical relationships among the related strengths of plastic concrete, the dimensional effect coefficients of compressive strength and splitting tensile strength with 100mm cubic specimen are 0.9375 and 0.8616 respectively compared with 150mm cubic specimen. Based on the analysis of test results, the conversion formulae of strength-related indicators and linear function relationship between axial compressive strength and curing ages are put forward respectively.

Abstract: A designed experimental study has been conducted to investigate the effect of clay dosage on mechanical properties of plastic concrete. The mechanical properties include compressive strength, splitting tensile strength, shear strength and elastic modulus. On the basis of the experimental results of the specimens of eight sets of mix proportions, the mechanism of action of clay on these mechanical properties has been analyzed in details. The results indicate that there is a tendency of decrease in the compressive strength, splitting tensile strength, shear strength and elastic modulus of plastic concrete with the increase of clay dosage. However, the internal friction angle of the shear specimens is increasing gradually with the increase of clay dosage. Further, the clay appears can improve the ductility of plastic concrete and this can help plastic concrete to bear larger deformation before failure.

Abstract: This study aimed to prepare a high performance plastic concrete made of epoxy resin and Portland type-I cement mixed with at least one inorganic solid waste of demercurated lighting phosphor powder or municipal solid waste incineration scrubber residue. The ratio between liquid epoxy resin and cement was 1:2; the scrubber residue and demercurated phosphor powder were added as modifiers for cement component in order to improve the strength and thermal properties of synthesized plastic concrete. The results indicate that, the addition of scrubber residue causes a decrease in both strength and thermal properties; whereas, the demercurated phosphor powder can replace 100% of the contents of cement without any significantly change in either strength or thermal properties. Atomic force microscopy and Raman spectroscopy were used to characterize the chemical structure of cured concrete and the results indicate that the surface softness increases with an increase in the mixed percentage of epoxy resin.