scholarly journals Compressive Strength of Interlocking Concrete Pavement Block influenced by Admixtures

2020 ◽  
Vol 14 ◽  

The interlocking concrete pavement blocks are quite commonly used to construct the pedestrian walkways and parking lots of transport infrastructure. Such blocks need adequate compressive strength to withstand the design live loads. In this paper, the influence of admixtures on the compressive strength of the blocks are studied through a series of laboratory investigations. The M35 grade of concrete conforming to the Indian Standard code of practice has been used with a standard superplasticizer as admixtures added at specified weights. The study implied that the use of admixtures alters the compressive strength of concrete blocks significantly.

The testing of concrete for its desired strength after casting is one of prime activities quality control of civil engineering project executions. The concrete is chiefly tested for its compressive strength and then the results are compared or checked with the desired design strength. In the era of computers used in every spectrum of life, the testing of materials and its results calculations also needs to be programed for calculations, validations and data storage. The cell based software do provide ease of calculations but storage and retrieval of data is difficult in those software. The current study is an effort to develop a program the calculations of compressive strength of concrete and flexural strength of the concrete as per Indian Standard Code of Practice. The standalone customized software used in calculations gives accurate and consistent results. Also, the validations programed with logics avoid hazy manual interpretations of the regulatory provisions and gives accurate results.


Author(s):  
Guilherme Aris Parsekian ◽  
André Luis Christoforo ◽  
Amanda Duarte Escobal Mazzú ◽  
Gláucia Maria Dalfré

abstract: It is extremely important that the quality control of the concrete block used in structural masonry is conducted based on standard procedures that allow reliable estimation of the properties of these components. This work aims to analyze and evaluate the influence of the concrete block moisture on the result of the compression test. Hollow concrete blocks were prepared and subsequently maintained in different environments for various periods of time and under different conditions of temperature and humidity to determine the influence of the type of drying on the relative humidity of the block at the time of testing and consequently on its compressive strength. As a conclusion, it can be stated that, because it is necessary to use water in the process, the grinding rectification of the faces of the blocks led them to have high humidity, above 70%. If tested in this condition, the results of the compressive strength tests will be lower than that of blocks under usual environmental conditions. No differences were found in the average block strength when they were kept dry in the controlled environment of the laboratory during periods of 24 or 48 h. After grinding, it is not necessary to dry the blocks inside an oven at 40ºC before the tests; simply leaving them at a usual room temperature of 23ºC and humidity of 40 ± 5% for 24h is sufficient. The attempt to accelerate drying in an oven at 100ºC is not adequate because this leads to an increase in the compressive strength. From the results, it was possible to determine expressions to correlate the compressive strength as a function of the moisture of the block at the time of the test. The best-fit expressions are distinct for each block type, but the formulations are consistent in indicating a considerable difference in resistance as a function of moisture.


2015 ◽  
Vol 7 (2) ◽  
pp. 91-96 ◽  
Author(s):  
Ayman Trad ◽  
Hassan Ghanem ◽  
Nivine Abbas ◽  
Ziad Hamdan

The compressive strength of concrete block masonry is dependent upon the unit compressive strength, the type of unit, the mortar and the form of masonry construction (Mirza et al. 1995). The design codes allow masonry compressive strength to be established (or better: estimated) by calculation, from tests, or from tabulated values. In this way the current European masonry standard EN 1996: Part 1-1 (LST EN 1996-1-1) tabulates the masonry strength for concrete blocks with thin layers of mortar. In France, doubts exist on the validity of these tabulated values for the blocks made with lightweight aggregates. To provide data for an extension of the use of the tabulated values for lightweight aggregates blocks and at the same time to provide input to the development of Eurocode 6, a major research program was set up. The research program aims to evaluate the mechanical strength of the thin joints hollow concrete masonry made with dense or lightweight aggregates. Tests have been carried out on a very large type of hollow blocks. Different geometries of blocks and different types of aggregates are tested. All these tests are based on CEN standards to meet Eurocode 6 requirements. This work proves that the formula proposed by Eurocode 6 to calculate the characteristic compressive strength of hollow concrete masonry are largely safe. It was also found that the strength of masonry depends only on the block resistance and is independent of the nature of aggregate.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Amalia Amalia ◽  
Agus Murdiyoto

ABSTRACTThis study aims to investigate the potential of gold mining tailings UPBE Pongkor as hollow concrete brick making material and investigate its properties. The study was conducted by making hollow concrete brick composition 1 PC: 8 aggregate, consisting of 4 variations of tailings as aggregate substitution, ie 0%, 25%, 50%, and 75% of the aggregate weight. The results showed that (1) the use of tailings as aggregate replacement in concrete hollow brick can reduce the compressive strength of concrete blocks, (2) can be used as a substitute Tailings aggregate up to 75%, wherein the composition produces hollow concrete bricks that still meets ISO standards for class IV concrete brick that can be used as non-structural partition wall, (3) the higher levels replace sand tailings, water absorption in hollow concrete brick is also higher, (4) weight content of concrete hollow brick using more and more tailings, bulk density is decreased.Key words : Hollow concrete brick, compressive strength, tailing of gold mining


2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Maria das Graças Duarte de Oliveira ◽  
Edgar Bacarji ◽  
Gilson Natal Guimaraes

RESUMO: Foi realizado um estudo experimental de vigas de alvenaria de concreto submetidas à flexão simples e as variáveis usadas foram a altura da seção transversal e a distribuição das barras da armadura longitudinal. Foram confeccionadas nove vigas com blocos e canaletas de concreto de resistência característica a compressão de 13 MPa. A altura da seção transversal foi definida pela quantidade de fiadas de blocos: uma, duas e três fiadas. As barras de aço da armadura longitudinal foram distribuídas na seção transversal, mantendo constante a taxa de armadura. Foram moldadas três vigas apenas com canaletas e sem estribos, pois seu uso é muito comum na região de Goiânia, GO. Os resultados obtidos foram confrontados com valores encontrados utilizando as recomendações de dimensionamento da norma NBR15961-1 (2011).  De modo geral, as vigas com estribos e com armadura longitudinal distribuídas nas diversas fiadas tiveram desempenho melhor, sendo estas mais dúcteis e mais seguras que as vigas apenas com canaletas e sem estribos. Essas vigas com estribos romperam por flexão e as cargas de ruptura excederam os valores calculados conforme as recomendações de norma. Já as vigas sem estribos romperam por cisalhamento com cargas de ruptura menor ou igual ao recomendado por norma. Este estudo mostra que não devem ser utilizadas vigas de alvenaria sem estribos. ABSTRACT: An experimental study of the flexural behavior of concrete masonry beams subjected to flexure was done and the variables used were the height of the cross section and the distribution of the longitudinal reinforcement along the layers of blocks. Nine concrete masonry beams were cast and tested with concrete blocks of 13 MPa compressive strength. The height of the cross section was defined by the number of blocks: one, two or three layers. The steel longitudinal reinforcement was distributed along the cross section, such that the steel arrangement gave the same steel reinforcing ratio for all beams. Three beams with lintels only and without stirrups were cast since its use if very common in the region of Goiania, GO. Results obtained were compared to those values obtained using recommendations prescribed in Brazilian code of practice NBR 15961-1 (2011). In general, beams with stirrups and with longitudinal reinforcement distributed along the height of the cross section had better performance, were more ductile and safer than beams without stirrups. These beams failed in flexure and ultimate loads were above those calculated using code recommendations. Beams without stirrups had a shear failure with ultimate loads lower than recommended by the code. This study shows that beams without stirrups should not be used.


2018 ◽  
Vol 9 (2) ◽  
pp. 67-73
Author(s):  
M Zainul Arifin

This research was conducted to determine the value of the highest compressive strength from the ratio of normal concrete to normal concrete plus additive types of Sika Cim with a composition variation of 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1 , 50% and 1.75% of the weight of cement besides that in this study also aims to find the highest tensile strength from the ratio of normal concrete to normal concrete in the mixture of sika cim composition at the highest compressive strength above and after that added fiber wire with a size diameter of 1 mm in length 100 mm with a ratio of 1% of material weight. The concrete mix plan was calculated using the ASTM method, the matrial composition of the normal concrete mixture as follows, 314 kg / m3 cement, 789 kg / m3 sand, 1125 kg / m3 gravel and 189 liters / m3 of water at 10 cm slump, then normal concrete added variations of the composition of sika cim 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1.5%, 1.75% by weight of cement and fiber, the tests carried out were compressive strength of concrete and tensile strength of concrete, normal maintenance is soaked in fresh water for 28 days at 30oC. From the test results it was found that the normal concrete compressive strength at the age of 28 days was fc1 30 Mpa, the variation in the addition of the sika cim additive type mineral was achieved in composition 0.75% of the cement weight of fc1 40.2 Mpa 30C. Besides that the tensile strength test results were 28 days old with the addition of 1% fiber wire mineral to the weight of the material at a curing temperature of 30oC of 7.5%.


Author(s):  
Oldřich Sucharda ◽  
David Mikolášek ◽  
Jiří Brožovský

Abstract This paper deals with the determination of compressive strength of concrete. Cubes, cylinders and re-used test beams were tested. The concrete beams were first subjected to three-point or fourpoint bending tests and then used for determination of the compressive strength of concrete. Some concrete beams were reinforced, while others had no reinforcement. Accuracy of the experiments and calculations was verified in a non-linear analysis.


2021 ◽  
Vol 13 (4) ◽  
pp. 2073 ◽  
Author(s):  
Hossein Mohammadhosseini ◽  
Rayed Alyousef ◽  
Mahmood Md. Tahir

Recycling of waste plastics is an essential phase towards cleaner production and circular economy. Plastics in different forms, which are non-biodegradable polymers, have become an indispensable ingredient of human life. The rapid growth of the world population has led to increased demand for commodity plastics such as food packaging. Therefore, to avert environment pollution with plastic wastes, sufficient management to recycle this waste is vital. In this study, experimental investigations and statistical analysis were conducted to assess the feasibility of polypropylene type of waste plastic food tray (WPFT) as fibrous materials on the mechanical and impact resistance of concrete composites. The WPFT fibres with a length of 20 mm were used at dosages of 0–1% in two groups of concrete with 100% ordinary Portland cement (OPC) and 30% palm oil fuel ash (POFA) as partial cement replacement. The results revealed that WPFT fibres had an adverse effect on the workability and compressive strength of concrete mixes. Despite a slight reduction in compressive strength of concrete mixtures, tensile and flexural strengths significantly enhanced up to 25% with the addition of WPFT fibres. The impact resistance and energy absorption values of concrete specimens reinforced with 1% WPFT fibres were found to be about 7.5 times higher than those of plain concrete mix. The utilisation of waste plastic food trays in the production of concrete makes it low-cost and aids in decreasing waste discarding harms. The development of new construction materials using WPFT is significant to the environment and construction industry.


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