scholarly journals Evaluation of the Effects of Coarse Aggregate Sizes on Concrete Quality

Author(s):  
Lawrence Echefulechukwu Obi

This work was necessitated by the observations made at construction sites where artisans and craftsmen were left alone in concrete production. It was discovered that they used inadequate quantity and size of coarse aggregates due to difficulty associated in the mixing as if the coarse aggregates were not needed in concrete production. The research has established that the coarse aggregates and their sizes play critical roles in the development of adequate strength in concrete. It was observed that with proper mixing, the slump test results did not witness shear or collapse type of slump rather there were true slump in all cases of the test. The workability decreased with slight differences when the coarse aggregate size was increased. The increase in the coarse aggregates yielded appreciable increase in the compressive strength. It can therefore be inferred that the quality of concrete in terms of strength can be enhanced through an increase in the coarse aggregate size when proper mix ratio, batching, mixing, transporting, placing and finishings are employed in concrete productions.

2018 ◽  
Vol 3 (1) ◽  
pp. 55
Author(s):  
Suhendra Suhendra

Aggregate quality is very influential on the strength of the resulting concrete. Both coarse and fine aggregates have various characteristics identified from laboratory test results. This study aims to examine the use of various aggregates for a quality of concrete. The coarse aggregate and the fine aggregate used are obtained from the nearest location to the work to be performed. The quality of the concrete reviewed is K-125, K-175 and K-225. The coarse aggregates used are 1-2 size (in cm), 2-3 size (in cm) crushed aggregate and coral. The fine aggregates used for each of the coarse aggregates are also different. The results showed that the coral aggregate did not meet the gradations of concrete aggregate. While the fine aggregate does not meet the gradation of concrete aggregate for the three types used. The concrete compressive strength test results show the use of coarse aggregates of 2-3 size of crushed and coarse aggregate of corals giving the average compressive strength value required for all planned concrete strength. While concrete using coarse aggregates of rocks of size 1-2 only meet the specified compressive strength, but does not meet the required compressive strength.Key words: Aggregates, concrete, compressive strength


2013 ◽  
Vol 811 ◽  
pp. 223-227
Author(s):  
Yong Ye ◽  
Hong Kai Chen ◽  
Yi Zhou Cai

The objective of this study is to investigate and evaluate the effect of coarse aggregates (aggregate size bigger than 2.36 mm) on the compressive strength and creep behavior of asphalt mixture. The variable that is mainly considered in the study is the gradation degradation of coarse aggregates. A kind of standard aggregate gradation and three kinds of degraded aggregate gradation mixture specimens are used. Uniaxial compression and static creep tests were realized at different loading conditions and temperatures. The test results on asphalt mixture showed that the compressive strength and creep behavior of asphalt mixture are significant affected by the different coarse aggregate gradations.


Author(s):  
S.E Ubi ◽  
P.O Nkra ◽  
R.B Agbor ◽  
D.E Ewa ◽  
M. Nuchal

This present research was on the comparison of the efficacious use of basalt and granite as coarse aggregates in concrete work. In order to obtain the basis for comparison, physical and structural tests were conducted on the different materials of the concrete and the concrete samples respectively. Physical test results revealed that basalt have a specific gravity of 2.8 and 2.5, while granite have a specific gravity of 2.9 and 2.6. In density, basalt have a density of 1554.55kg/m3 while granite had a density of 1463.64kg/m3. Aggregate impact test conducted on both aggregates revealed a percentage of 11.05% for basalt and 12.63% for granite. The following structural tests were carried out: compressive strength tests, flexural and tensile strength test and the comparative results are as follows. Compressive strength for basalt 36.39N/mm2 while 37.16N/mm2 for granite. 24.81N/mm2 tensile strength for basalt while 12.57N/mm2 for granite, 31.83N/mm2 flexural strength for basalt while 27.97N/mm2 for granite. From the above results, it can be deduced that basalt has higher strength properties than granite. Therefore, more suitable for coarse aggregate in achieving higher strength with some quantity of other composition of the concrete mix when compared to granite.


2018 ◽  
Vol 280 ◽  
pp. 399-409
Author(s):  
Nurul Noraziemah Mohd Pauzi ◽  
Maslina Jamil ◽  
Roszilah Hamid ◽  
Muhammad Fauzi Mohd Zain

The study on the substitution for natural coarse aggregates using waste CRT funnel glass in spherically shapes is still limited. In this paper, the waste CRT glass has been processed to form a spherical CRT glass (GS) and crushed CRT glass (GC), which were used as a coarse aggregate in concrete production. Results indicated that the inclusion of GS and GC has lower the compressive strength and decreased the rate of capillary water absorption of concrete. It was demonstrated that the morphology properties of GS and GC (shape, surface texture, size, grading) is significantly affected the concrete properties.


Author(s):  
Taisir S. Khedaywi ◽  
Egons Tons

Higher costs and possible restricted availability of asphalt have stimulated research and discussion on how to reduce the amount of asphalt in bituminous mixes without sacrificing service. A hypothesis was proposed suggesting that for each coarse aggregate type with different surface characteristics there is a specific fine aggregate size that contributes to developing an interlocking mechanism between the surfaces of coarse aggregates when they are combined in a bituminous mix. To test this hypothesis, two types of coarse aggregates having different surface characteristics or rugosity, limestone and rounded gravel, were used. For each aggregate, two one-size fractions were tested—19 mm to 25 mm and 6.4 mm to 4.75 mm. One type of fine aggregate (limestone) with five one-size fractions was used. Four flow binder film thicknesses were chosen. The packing volume and rugosity concepts were the theoretical basis. Asphalt and aggregate mixes were tested in compression. The results were evaluated by the use of regression equations. Graphical presentations and illustrations were used as necessary. Unconfined compression test results showed that for one-size limestone coarse aggregate, the highest strength values were associated with No. 60 to No. 80 fines in the mix and for one-size rounded gravel coarse aggregate, the highest strength occurred when No. 200 to No. 270 fines were added to the mix. The highest strength was associated with 50 μm flow binder film thickness for all mixes.


2018 ◽  
Vol 147 ◽  
pp. 04011
Author(s):  
Anggun Farida ◽  
Iwan Juwana ◽  
Hazairin

Used reagent glass bottles are solid waste that people rarely pay attention to in Indonesia. In many cases, the bottles are disposed off without proper handling and treatment, due to the lack of research and information. One potential treatment for such waste is to transform the glass bottles into raw materials for concretes. The objective of the research is to determine the influence of crushed glass particles to the quality of the concrete. The potential reduction of glass bottles will also be calculated.The glass bottles used in this research are the amber ones. The concrete was designed to meet the K225 type requirements. Experiments were done using 0%, 25%, 50%, and 75% of crushed glass particles. In the concrete production, these crushed glass particles will replace the coarse aggregates. This research measured compressive strength and Toxicity Characteristic Leaching Procedures (TCLP) tests in accordance to SNI and TCLP Extraction Procedures from BAPEDAL. At the end, it was found that the concretes using all variations meet the requirements. As for the TCLP, it showed that concentrations of Cr6+ for the concretes using all variations were all under the threshold, according to Hazardous National Regulation 101/2014. The potential reduction is 600 – 2100 waste bottles.


2021 ◽  
Vol 2 (1) ◽  
pp. 46-54
Author(s):  
Neti Rahmawati ◽  
Irwan Lakawa ◽  
Sulaiman Sulaiman

Concrete is one of the most widely used building materials today interms of physical construction. Concrete is made from a mixture offine, coarse aggregate, cement, and water with a certain ratio, aswell as materials that are usually added to the concrete mixtureduring or during mixing, to changing the properties of concrete tomake it more suitable in certain jobs and more economical, can alsobe added with certain other mixed materials as needed if deemednecessary. Seashells can be used to mix concrete. This study aims todetermine whether the addition of shells aggregate shells in aconcrete mixture can affect the mechanical properties of concrete.The specimens used are in the form of cubes with a size of 15cm x 15cm x 15 cm, consisting of additional concrete coarse and fineaggregate with shell substitution percentage of 0%, 15%, 20% with atotal sample of 45, with the planned concrete quality of K225. Theuse of sea shells in increasing the compressive strength of concrete isbetter used as fine aggregate than coarse aggregate. The use of seashells as a substitute for fine aggregates achieves maximum resultsat 20% composition.


2020 ◽  
Vol 28 (1) ◽  
pp. 106
Author(s):  
Rahelina Ginting ◽  
Winarko Malau

Concrete work is widely used in construction projects now. To get a good quality concrete depends very much on the quality of the constituent materials, namely cement, water, fine aggregate, coarse aggregate, and also the process of working or stirring. In this research, 27 MPa concrete compressive strength will be investigated with various stirring methods (Manual Mix, Molen Mix and Ready Mix). These three methods of stirring certainly have their respective uses in the process, usually Manual, Molen and Ready Mix are used depending on the conditions of the project being worked on. From this test, results are obtained by means of manual stirring, Molen stirring and Ready Mix with compressive strength average: (266,467 kg / cm2) (278,368 kg / cm2) (284,595 kg / cm2). The results of the study stated that the research carried out fulfilled the estimation target 'c = 27 Mpa.


2021 ◽  
Vol 4 (2) ◽  
pp. 159
Author(s):  
Ary Prastowo ◽  
Ahmad Ridwan ◽  
Edy Gardjito ◽  
Zendy Bima Mahardana

Concrete is a building construction material that has an important role. Concrete itself tends to have strong properties in resisting compressive forces, but weak in resisting tensile or flexural forces. The use of additives in concrete is an option to improve the basic properties of concrete. Latex or rubber latex is one of the natural materials that can be used in concrete mixtures. Its adhesive properties can be utilized in improving the quality of concrete. This study aims to determine the compressive strength and flexural strength of concrete with the addition of latex. The research was conducted experimentally by making concrete specimens in the laboratory. The addition of latex by 10% and 30% with a planned concrete quality of fc' 29.5 MPa. The test object used is a cylinder measuring 15x30 cm and a beam measuring 15x15x30 cm. The tests carried out were testing the compressive strength and flexural strength at the age of 28 days. The results showed that the highest compressive strength was at the addition of 10% latex with a value of 9.96 MPa. While the highest flexural strength value obtained was 3.20 Mpa at the addition of 10% Latex or. From these results it can be seen that the addition of latex has not been able to improve the quality of concrete and has not been able to increase the compressive strength or flexural strength of concrete. So that these results can be used as research development or concrete production.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
N. N. M. Pauzi ◽  
◽  
M. R. Karim ◽  
M. Jamil ◽  
R. Hamid ◽  
...  

The aim of this study is to conduct an experimental investigation on the influence of complete replacement of natural coarse aggregate with spherically-shape and crushed waste cathode ray tube (CRT) glass to the aspect of workability, density, and compressive strength of the concrete. After characterizing the glass, a group of concrete mixes was prepared to contain a 40% spherical CRT glass and 60% crushed CRT glass as a complete (100%) replacement of natural coarse aggregates. From a total of 16 types of concrete mixes, the optimum proportion was selected based on its best performance. The test results showed that the use of spherical and crushed glass that possesses a smooth surface, rounded, irregular and elongated shape, and low water absorption affects the workability of concrete. Due to a higher specific gravity of crushed glass, concrete mixes containing CRT glass had a higher density compared to ordinary concrete. Despite the spherical and crushed CRT glass being stronger than gravel, the results revealed a reduction in compressive strength of the concrete. However, using a lower water to binder (w/b) ratio and a higher superplasticizer (SP) dosage, it is found to enhance the compressive strength of 60.97 MPa at 28 days that is lower by 13% than the control specimen. These findings indicate that waste CRT glass in the form of spherical and crushed could be used as an alternative of coarse aggregate that may pave the way for the disposal of hazardous e-waste.


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