scholarly journals A Study of the Replacement of Natural Coarse Aggregate by Spherically-Shaped and Crushed Waste Cathode Ray Tube Glass in Concrete

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.

2018 ◽  
Vol 7 (4.20) ◽  
pp. 395
Author(s):  
Laith Mohammed Ridha Mahmmod Wajde ◽  
S. S. Alyhya Zainab ◽  
M. R. Abdul Rasoul ◽  
Abdulrasool T. Abdulrasool ◽  
. .

Properties of coarse aggregate such as texture have a significant influence on the performance of fresh and hardened concrete. A smooth surface can enhance workability, yet a rougher one offers a stronger bond between aggregate and paste, resulting in higher strength. This research aims to roughen the texture of white smoothed aggregate by using cement-iron filings mortar with the aid of microwave maturation to accelerate the adhesion process of mortar-aggregate surface. The mortar was prepared by mixing an equal weight of cement and iron filings, of a particular size, with sand. Four different periods (2, 4, 6 and 8 mints.)  of microwave treatment in addition to water curing were considered plus one reference mortar which cured in only air for 24 hrs. The treated aggregate was then used for casting concrete specimens with a w/c ratio of 0.5 in which their properties being determined by means of density, compressive and tensile strengths observations. The main findings revealed that the concrete specimens contained microwave treated aggregate attained higher compressive strength compared with those treated in the air. Data also showed that concrete specimens with microwave treated aggregate possess better tensile properties as a consequence of the improvement in the transition zone.   


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.


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.


2021 ◽  
Vol 1030 ◽  
pp. 88-93
Author(s):  
Adeline Ling Ying Ng ◽  
Hock Rui Liew ◽  
Yew Ching Wong

This paper studies the effect of replacing coarse aggregates with manganese slag on the mechanical properties of concrete. Air-cooled granulated manganese slag was used. The control sample was designed to achieve concrete strength of 30 MPa at 28 days. Tests were conducted on five different compositions of concrete having manganese slag to coarse aggregates ratios of 0, 0.2, 0.3, 0.4, and 1. The specimens were tested at 7, 14, and 28 days for their compressive and flexural strength. Test results revealed that all manganese slag concrete specimens had improved compressive and flexural strength. The maximum compressive strength achieved was 43.54 MPa, increased by 16% of the control specimen and the maximum flexural strength achieved was 4.50 MPa, increased by 22% of the control specimen. Both results were obtained in concrete with 0.4 manganese slag to coarse aggregate ratio. Besides, the study also showed that it might be possible to substitute all coarse aggregates in concrete with manganese slag without any loss in strength. However, it was observed that the concrete workability decreased when manganese slag was added. Nonetheless, this could be corrected using superplasticizer.


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.


2014 ◽  
Vol 13 (2) ◽  
pp. 065-072
Author(s):  
Waldemar Budzyński ◽  
Jacek Góra ◽  
Wojciech Piasta ◽  
Tadeusz Turkiewicz

Test results concern modulus of elasticity and compressive strength of ordinary concretes made of various coarse aggregates from igneous rocks. Test results of some properties of these aggregates (3 crushed granites, 3 basalts, granodiorite, natural gravel) are also considered. The variable factor of the studies is the type of coarse aggregate. According to the analyses of regression and correlation there occurs a significant effect of the aggregate grinding ratio on the modulus of elasticity of concretes contrary to insignificant effect of the compressive strength. The modulus of elasticity of 4 concretes from Polish and Ukrainian granites and basalt aggregates is lower than respective standard values of the modulus.


Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 556
Author(s):  
Muhammad Faisal Javed ◽  
Afaq Ahmad Durrani ◽  
Sardar Kashif Ur Rehman ◽  
Fahid Aslam ◽  
Hisham Alabduljabbar ◽  
...  

Numerous research studies have been conducted to improve the weak properties of recycled aggregate as a construction material over the last few decades. In two-stage concrete (TSC), coarse aggregates are placed in formwork, and then grout is injected with high pressure to fill up the voids between the coarse aggregates. In this experimental research, TSC was made with 100% recycled coarse aggregate (RCA). Ten percent and twenty percent bagasse ash was used as a fractional substitution of cement along with the RCA. Conventional concrete with 100% natural coarse aggregate (NCA) and 100% RCA was made to determine compressive strength only. Compressive strength reduction in the TSC was 14.36% when 100% RCA was used. Tensile strength in the TSC decreased when 100% RCA was used. The increase in compressive strength was 8.47% when 20% bagasse ash was used compared to the TSC mix that had 100% RCA. The compressive strength of the TSC at 250 °C was also determined to find the reduction in strength at high temperature. Moreover, the compressive and tensile strength of the TSC that had RCA was improved by the addition of bagasse ash.


2008 ◽  
Vol 3 (4) ◽  
pp. 130-137 ◽  
Author(s):  
R Kumutha ◽  
K Vijai

The properties of concrete containing coarse recycled aggregates were investigated. Laboratory trials were conducted to investigate the possibility of using recycled aggregates from the demolition wastes available locally as the replacement of natural coarse aggregates in concrete. A series of tests were carried out to determine the density, compressive strength, split tensile strength, flexural strength and modulus of elasticity of concrete with and without recycled aggregates. The water cement ratio was kept constant for all the mixes. The coarse aggregate in concrete was replaced with 0%, 20%, 40%, 60%, 80% and 100% recycled coarse aggregates. The test results indicated that the replacement of natural coarse aggregates by recycled aggregates up to 40% had little effect on the compressive strength, but higher levels of replacement reduced the compressive strength. A replacement level of 100% causes a reduction of 28% in compressive strength, 36% in split tensile strength and 50% in flexural strength. For strength characteristics, the results showed a gradual decrease in compressive strength, split tensile strength, flexural strength and modulus of elasticity as the percentage of recycled aggregate used in the specimens increased. 100% replacement of natural coarse aggregate by recycled aggregate resulted in 43% savings in the cost of coarse aggregates and 9% savings in the cost of concrete.


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