scholarly journals Constitutive Model of Uniaxial Compressive Behavior for Roller-Compacted Concrete Using Coal Bottom Ash Entirely as Fine Aggregate

Buildings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 191
Author(s):  
Yu Li ◽  
Li Li ◽  
Vivek Bindiganavile

Coal bottom ash (CBA) is one of the by-products that can be employed as fine aggregate to replace natural sand in concrete. Owing to the very low water demand, roller-compacted concrete (RCC) has the potential to use CBA as fine aggregate at a high proportion. However, little research about RCC using CBA entirely as fine aggregate has been conducted. In this study, the uniaxial compressive strength, deformation, stress–strain curves, and splitting tensile strength of CBA-containing RCC (CBA RCC) were studied to bridge this gap. The compressive strength, elasticity modulus, and splitting tensile strength of all mixtures decreased with increasing CBA content. The relationship between compressive strength and splitting tensile strength of CBA RCC was proposed, which is very close to that recommended by the CEB-FIP code. The uniaxial compressive constitutive model based on the continuum damage theory can well illustrate the stress–strain relationship of CBA RCC. The growth process of damage variable demonstrates the hybrid effect of coarse aggregate, cement, and compacting load on delaying damage under uniaxial compression. The theoretical formula can also accurately illustrate the stress–strain curves of RCC presented in the literature studies.

2020 ◽  
Vol 6 (1) ◽  
pp. 13 ◽  
Author(s):  
Noraziela Syahira Baco ◽  
Shahiron Shahidan ◽  
Sharifah Salwa Mohd Zuki ◽  
Noorwirdawati Ali ◽  
Mohamad Azim Mohammad Azmi

Coal Bottom Ash (CBA) is a mineral by-product of thermal power plants obtained from the combustion of coal. In many countries, CBA wastes are identified as hazardous materials. The utilization of CBA can help in alleviating environmental problems; thus, this research was carried out to explore the possibility of its use as cement replacement in concrete manufacturing. Presently, In Malaysia, research that concerns about the use of CBA as cement replacement is very limited. Therefore, this study was aimed to investigate the properties of CBA as cement replacement and to identify the optimum percentage of untreated CBA as cement replacement. The CBA used in this study were taken from the Tanjung Bin power plant. In this research, the amount of CBA in the concrete mixture varied from 20% to 40% to replace cement. The properties of concrete containing CBA as cement replacement was examined through slump test, sieve analysis, concrete compressive strength test and splitting tensile strength test. The compressive strength test and splitting tensile strength test were performed at 7 and 28 days of curing time. Based on this research, it can be concluded that the optimum percentage of CBA as cement replacement is 25% for a curing time of both 7 and 28 days with the concrete compression strength of 45.2 MPa and 54.6 MPa, respectively. Besides, the optimum percentage for tensile strength is also at 25% CBA for a curing period of both 7 and 28 days with the tensile strength of 2.91 MPa and 3.28 MPa, respectively. 


Buildings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 44
Author(s):  
Tariq Ali ◽  
Abdul Salam Buller ◽  
Fahad ul Rehman Abro ◽  
Zaheer Ahmed ◽  
Samreen Shabbir ◽  
...  

Cement production produces a high amount of carbon dioxide, which has a negative impact on the environment. By utilizing waste products instead of cement, environmental degradation can be reduced. The current study was undertaken to study the mechanical and durability performance of concrete by replacing 7.5%, 10%, and 12.5% silica fume (SF) of cement weight. Additionally, coal bottom ash (CBA) was also substituted as fine aggregates with 10%, 20%, and 30%. Compressive strength and indirect tensile strength were the major parameters regarding mechanical properties, while corrosion analysis and sulfate attack were set for durability performance. Sixteen mixes were prepared including a control mix. Out of these, three mixes contained SF, three mixes contained CBA, and eight mixes contained both SF and CBA with 1:2:4 ratio at 0.5 w/b ratio. The results concluded that the addition of 12.5% SF and 30% CBA gives optimum compressive strength and tensile strength. Furthermore, using the SF and CBA reduces the workability of concrete. Furthermore, the use of these byproducts increased the durability in terms of corrosion and sulfate attack.


2019 ◽  
Vol 276 ◽  
pp. 01014
Author(s):  
I Made Alit Karyawan Salain ◽  
I Nyoman Sutarja ◽  
Teguh Arifmawan Sudhiarta

This experimental study presents the properties of highperformance concrete (HPC) made by partially replacing type I Portland cement (OPC) with class C fly ash (CFA). The purpose of this study is to examine, with hydration time, the development of the compressive strength, the splitting tensile strength and the permeability of HPC utilizing different quantity of CFA. Four HPC mixtures, C1, C2, C3, and C4, were made by utilizing respectively 10%, 20%, 30% and 40% of CFA as replacement of OPC, by weight. One control mixture, C0, was made with 0% CFA. The mix proportion of HPC was 1.00 binder: 1.67 fine aggregate: 2.15 coarse aggregate with water to binder ratio 0.32. In each mixture, it was added 5% silica fume and 0.6% superplasticizer of the weight of the binder. Tests of HPC properties were realized at the age of 1, 3, 7, 28, and 90 days. The results indicate that CFA used to partially replace OPC in HPC shows adequate cementitious and pozzolanic properties. The compressive strength and the splitting tensile strength of HPC increase while the permeability coefficient decreases with increasing hydration time. It is found that the optimum replacement of OPC with CFA is 10%, however the replacement up to 20% is still acceptable to produce HPC having practically similar harden properties with control mixture. At this optimum replacement and after 90 days of hydration, the compressive strength, the splitting tensile strength and the permeability coefficient can reach 68.9 MPa, 8.3 MPa and 4.6 E-11 cm/sec respectively. These results are 109%, 101%, and 48% respectively of those of control mixture.


Copper slag is a rough blasting grit or a by-product acquired by the process of copper smelting and refining. These copper slags are recycled for copper recovery. In this paper, we analysed copper slag’s feasibility and evaluate its total competence in M25 grade concrete. In this observation, a concrete mixture is applied with copper slag as a fine aggregate ranging from 0%, 20%, 40%, 60%, 80%, and 100% respectively. The strength of copper slag’s implementation is accomplished on the basis of concrete’s flexural strength, compressive strength and splitting tensile strength. From the obtained results, in concrete 40% percentage of copper slag is used as sand replacement. On 28 days, the modulus of elasticity increased up to 32%, the compressive strength increased up to 34% and flexural strength is increased to 6.2%. From this experiment, it is proved technically that replacing sand using copper slag as a fine mixture in M25 grade concrete.


2014 ◽  
Vol 665 ◽  
pp. 147-150 ◽  
Author(s):  
Ping Hua Zhu ◽  
Yi Lei

The strength properties of recycled aggregate concrete (RAC) using aggregates from repeatedly recycling concrete waste were studied. The relationships between cube compressive strength and splitting tensile strength and between each strength and replacement ratio of recycled aggregate to natural aggregate were established. The results showed that the strength properties of RAC with the design strength of 30MPa can be satisfied when the quality of recycled coarse and fine aggregates met respectively the needs of Grade II in GB/T25177-2010 and Grade III in GB/T25176-2010, with the replacement ratio to natural coarse aggregate and natural fine aggregate no more than 70% and 50%. Both strengths decreased and then increased for a while before descending again with increasing replacement ratio of recycled coarse aggregate, and decreased continuously with the increase of replacement ratio of recycled fine aggregate. The relationship between cube compressive strength and splitting tensile strength of RAC was found to be exponential function.


2013 ◽  
Vol 701 ◽  
pp. 12-16 ◽  
Author(s):  
Mohd Irwan Juki ◽  
Khairunnisa Muhamad ◽  
Mahamad Mohd Khairil Annas ◽  
Koh Heng Boon ◽  
Norzila Othman ◽  
...  

This paper describes the experimental investigation to develop the concrete mix design Nomograph for concrete containing PET as fine aggregate. The physical and mechanical properties were determined by using mix proportion containing 25%, 50% and 75% of PET with water cement ratio (w/c) 0.45, 0.55 and 0.65. The data obtained showed that the inclusion of PET aggregate reduce the strength performances of concrete. All the data obtained were combined into one single graph to develop a preliminary mix design nomograph for PET concrete. The nomograph consist of ; relationship between compressive strength and water cement ratio; relationship between splitting tensile strength water cement ratio; relationship between splitting tensile strength and PET percentage and relationship between compressive strength and PET percentage. The mix design nomograph can be used to assists in selecting the proper mix proportion parameters based on the criteria required.


2015 ◽  
Vol 744-746 ◽  
pp. 1412-1415 ◽  
Author(s):  
Zong Ming Jia ◽  
Qing Han ◽  
Ming Hao Liu

Designing recycled concrete mixture proportion of different recycled coarse and fine aggregate replacement content by pulp content ,then testing compressive strength and splitting tensile strength. The text results show that: With the increasing of recycled aggregate content , the compressive strength and splitting tensile strength of recycled aggregate concrete trended to decrease. Compared to recycled coarse aggregate, recycled fine aggregate impact on the properties of recycled concrete is greater. Establishing the compressive strength and splitting tensile strength formula of recycled concrete based on a lot of experimental results.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7531
Author(s):  
Afnan Nafees ◽  
Muhammad Faisal Javed ◽  
Sherbaz Khan ◽  
Kashif Nazir ◽  
Furqan Farooq ◽  
...  

Silica fume (SF) is a mineral additive that is widely used in the construction industry when producing sustainable concrete. The integration of SF in concrete as a partial replacement for cement has several evident benefits, including reduced CO2 emissions, cost-effective concrete, increased durability, and mechanical qualities. As environmental issues continue to grow, the development of predictive machine learning models is critical. Thus, this study aims to create modelling tools for estimating the compressive and cracking tensile strengths of silica fume concrete. Multilayer perceptron neural networks (MLPNN), adaptive neural fuzzy detection systems (ANFIS), and genetic programming are all used (GEP). From accessible literature data, a broad and accurate database of 283 compressive strengths and 149 split tensile strengths was created. The six most significant input parameters were cement, fine aggregate, coarse aggregate, water, superplasticizer, and silica fume. Different statistical measures were used to evaluate models, including mean absolute error, root mean square error, root mean squared log error and the coefficient of determination. Both machine learning models, MLPNN and ANFIS, produced acceptable results with high prediction accuracy. Statistical analysis revealed that the ANFIS model outperformed the MLPNN model in terms of compressive and tensile strength prediction. The GEP models outperformed all other models. The predicted values for compressive strength and splitting tensile strength for GEP models were consistent with experimental values, with an R2 value of 0.97 for compressive strength and 0.93 for splitting tensile strength. Furthermore, sensitivity tests revealed that cement and water are the determining parameters in the growth of compressive strength but have the least effect on splitting tensile strength. Cross-validation was used to avoid overfitting and to confirm the output of the generalized modelling technique. GEP develops an empirical expression for each outcome to forecast future databases’ features to promote the usage of green concrete.


2015 ◽  
Vol 735 ◽  
pp. 122-127 ◽  
Author(s):  
Sikiru Oritola ◽  
Abd Latif Saleh ◽  
Abdul Rahman Mohd Sam

This paper reports preliminary findings on the properties of concrete produced using iron ore tailings obtained from ZCM Minerals SDN BHD located in Kotta Tingi, Johor, Malaysia. The Iron Ore Tailings (IOT’s) a waste product, with particle size range from (850μm - 75μm) obtained from Iron Ore Processing was utilized as fine aggregate to produce concrete. Based on British Standard (BS) guidelines, normal concrete mix was designed. Five types of concrete samples (C0, C1, C2, C3, and C4) were produced, with the percentage of tailings used to replace sand as fine aggregate ranging from 0 to 40[%]. The reference sample is C0 with no tailings and the four others, containing tailings at 10[%] intervals. The effect of iron ore tailings on the consistency of the fresh concrete were studied, as well as the density, compressive strength, flexural strength and splitting tensile strength, of the hardened concrete. The results of the consistency tests on concrete shows that the slump values ranges from 81 to 53[mm] from concrete sample C0 to C4 respectively, while the compacting factor values ranges from 0.92 to 0.89 respectively. The density of the produced concrete cube samples falls within the range 2350 to 2430[kg/m3]. The concrete sample C3 gave the highest compressive strength value of 43.70[N/mm2]. The concrete sample C3 also gave the highest flexural strength value of 4.79[N/mm2], while the The concrete sample C4 gave the highest splitting tensile strength value of 4.0[N/mm2] after curing period of 28[days].


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