scholarly journals EVALUATE THE INFLUENCE OF STEEL FIBERS ON THE STRENGTH OF CONCRETE USING PLASTIC WASTE AS FINE AGGREGATES

Author(s):  
Samiullah Qazi

The plastic existence in abundance and its low biodegradability affect the environment. In recent years, researchers have tested numerous recycling techniques. However, each has its demerits. One such technique is recycling plastic as aggregates in concrete. It improves the concrete thermal insulation but depreciates its compressive and tensile strength, which is its core property in the construction industry. The objective of this research work is to efficiently utilize the plastic aggregate in concrete without deteriorating its strength with the use of steel fibers. In total eight concrete mix configurations were studied in this research. The result discussion includes compressive strength, split tensile test, and toughness index. The steel fiber used in the concrete mix with recycled plastic as fine aggregates improved the concrete strength. Its effects increase with an increase in % vol replacement of plastic aggregates with fine aggregates from 5 to 20.

2021 ◽  
Vol 920 (1) ◽  
pp. 012034
Author(s):  
A A Shamilah ◽  
M ’A A Hamid ◽  
B N Faizah ◽  
A R Mustaqqim

Abstract 80% of the water supplied, normally comes out as wastewater either domestic or industrial. The utilization of wastewater in concrete will reduce potable water usage in the construction industry. Approximately 150 litres of water are required for lm3 of concrete without considering other applications of water in the concrete industry. This research study has investigated the performance of concrete using wastewater. 60 total number of concrete cubes have been designed and constructed using 10%, 20%, 30% and 100% of wastewater. The experimental data indicated that 30% of wastewater content in the concrete mix have increased 18% of the concrete strength compared with the control sample. Meanwhile, the result of the X-Ray Fluorescence Test (XRF) test for the concrete sample recorded that the CA is higher than the 30% concrete sample.


2021 ◽  
Vol 1 (1) ◽  
pp. 1-14
Author(s):  
Nurul Noraziemah Mohd Pauzi

The issue of the cathode ray tube (CRT) technology facing its end-of-time and increasing quantities across the globe has acquired the responsiveness of many researchers. The use of waste CRT glass as a construction material has fascinated them due to its significant advantage in recycling the hazardous and non-biodegradable waste CRT glass. However, lack of knowledge about the effects and features of CRT glass as a construction material could be a hindrance to the excessive utilization of waste CRT glass. Therefore, in order to establish the idea of using CRT waste glass as a more common construction material, this paper reviews several recycling techniques of CRT glass and further detail on the workability, density, and compressive strength properties of concrete and mortar using CRT glass (treated or untreated) as fine aggregates. The review showed that, generally, the use of CRT glass as a complete or partial replacement of natural sand shows a slight increase in density, workability, and concrete strength compared to conventional concrete. However, there are no clear trends that can be concluded as this review also showed that various factors influenced its performance, such as percentage replacement, particle size, lead (Pb) content, and types of admixtures.


2018 ◽  
Vol 25 (5) ◽  
pp. 927-937 ◽  
Author(s):  
Khuram Rashid ◽  
Sana Nazir

AbstractConservation of natural resources, healthy environments, and optimal utilization of waste materials are intimate needs of the present time, and this research work was carried out to fulfill these needs. In this experimental and analytical study, concrete was prepared by replacing natural fine aggregates with two types of used foundry sands by 10%, 20% and 30% (by volume). The properties of fresh and hardened concrete were investigated and compared with a replacement amount of fine aggregates from 0% to 30%. Compressive strength was evaluated after 7, 28 and 63 days of moist curing. Along with compressive strength, the modulus of elasticity was also investigated and a reduction in compressive strength and modulus of elasticity was observed with the increase in the amount of used foundry sand. A prediction formula was proposed to predict the compressive strength, and verified by current experimental observations and also with a large database that was also established in this work. The prediction formula may be considered as very helpful for predicting the potential of using used foundry sand as an aggregate in concrete.


2017 ◽  
Vol 17 (3) ◽  
pp. 183-197 ◽  
Author(s):  
Carlos Torres Formoso ◽  
Lucila Sommer ◽  
Lauri Koskela ◽  
Eduardo Luís Isatto

Abstract Making-do has been pointed out as an important category of waste in the construction industry. It refers to a situation in which a task starts or continues without having available all the inputs required for its completion, such as materials, machinery, tools, personnel, external conditions, and information. By contrast, the literature points out that improvisation is a ubiquitous human practice even in highly structured business organizations, and plays an important role when rules and methods fail. The aim of this paper is to provide some insights on the nature of making-do as a type of waste, based on two exploratory case studies carried out on construction sites. The main contributions of this research work are concerned with the identification of different categories of making-do and its main causes. This paper also discusses some strategies for reducing making-do on construction sites.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Apeesada Sompolgrunk ◽  
Saeed Banihashemi ◽  
Saeed Reza Mohandes

Purpose The purpose of this study is to identify and analyse the key measurable returning factors, value drivers and strategic benefits associated with building information modelling (BIM) return on investment (ROI). The findings of this study provide researchers and practitioners with up-to-date information in formulating appropriate strategies to quantify the monetary value of BIM. The suggested research agenda provided would also advance what is presently a limited body of knowledge relating to the evaluation of BIM ROI. Design/methodology/approach To fill the identified gap, this study develops a comprehensive systematic review of mainstream studies on factors affecting BIM ROI published from 2000 to 2020. A total of 23 academic records from different sources such as journals, conference proceedings, dissertation and PhD theses were identified and thoroughly reviewed. Findings The reported BIM ROI ranged greatly from −83.3% to 39,900%. A total of 5 returning factors, namely, schedule reduction and compliance, productivity improvement, request for information reduction, rework reduction and change orders reduction were identified as the most commonly reported factors that influence BIM ROI. Four quantification techniques including general assumptions-based theoretical model, perceived BIM ROI based on survey, factors affecting BIM ROI with no reported ROI and quantified BIM ROI based on a case study were observed and pointed out in the review, together with their limitations. Finally, three major gaps were raised as the lack of consideration on the likelihood of BIM assisting in a construction project, intangible returning factors influencing BIM-based projects and industry standards in benchmarking BIM ROI. Practical implications The outcomes of this study would assist practitioners by providing the current evaluation techniques that address the limitations with BIM investment and present issues relating to the economic evaluation of BIM in the construction industry. It is also expected that presenting a deeper and wider perspective of the research work performed until now will direct a more focussed approach on productivity improvement efforts in the construction industry. Originality/value This study identifies and analyses the key measurable returning factors, value drivers and strategic benefits associated with BIM ROI on an industry scale rather than a particular organisation or a project scale.


1997 ◽  
Vol 1575 (1) ◽  
pp. 92-101
Author(s):  
Richard K. Smutzer ◽  
Sedat Gulen ◽  
Youlanda K. Belew ◽  
Virgil L. Anderson

The Indiana Department of Transportation is involved in preparing statistically sound specifications for strong and durable concrete used in quality assurance programs. Previous laboratory studies relating concrete strength to air content and concrete mix designs dealt with variation in compressive strength. This study searched for a statistically sound relationship between air content, concrete mix designs, and flexural strength. This study also developed a high-pressure method of hardened concrete air content determination. Sixty-four independent batches (combinations) of concrete were produced, each batch was subjected to a total of 24 tests—4 plastic and 20 hardened. The design factors were aggregate type and gradation, plastic air content, cement, and pozzolanic content and testing operator. After plastic testing, three flexural strength beams were cast from each batch of concrete. The experimental design response variables consisted of flexural, compressive, and split tensile strength along with pulse velocity. Analysis of variances, indicated that the optimum flexural strength could be obtained using as-received stone course aggregate and an air content of between 6 percent and 7.9 percent, with no fly ash. A high-pressure air meter, similar to the meter developed by the Army Corps of Engineers, was used. A strong statistical correlation of determination, r2 = 0.94, was obtained between plastic and the hardened concrete air content using this meter.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Antonio Brencich ◽  
Rossella Bovolenta ◽  
Valeria Ghiggi ◽  
Davide Pera ◽  
Paolo Redaelli

The issue of concrete strength often arises in civil engineering practice, either due to quality control of new constructions or due to the assessment of existing structures. To this aim, one of the most widely spread techniques is the rebound hammer (Schmidt hammer) test, for which calibration is still related to the original Schmidt curve dating back to the early 50’s. In spite of the large amount of research work performed in the last decades, the uncertainties of the rebound test are still not clearly quantified and open to further insight. This paper presents and discusses a wide research campaign on laboratory specimens and on third-party specimens delivered to the Laboratory for Building Materials of the University of Genoa, Italy, for standard quality controls. While it is well known that moisture content, surface finishing, and concrete maturity strongly affect the test result, the effect of the stress state has not yet been studied and is found in this research to be a further parameter affecting the test reliability. The final outcome of all the uncertainties is variability in estimated concrete strength as large as ±70%; additionally, some issues are discussed on the intrinsic uncertainty of this test. As already demonstrated by many authors, the results of this research also show that a universal calibration curve to be used for any concrete, in any condition, conceptually does not exist.


Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 5
Author(s):  
Tudor Panfil Toader ◽  
Anamaria Cătălina Mircea

Concrete is the most used material in the construction industry, being prone to cracking. Following the action of aggressive external agents, through cracks, access routes to the embedded reinforcement are created. By enclosing in concrete various materials that can induce the self-healing property, by taking actions when the cracks appear, the access of the external aggressive agents to the reinforcement can be stopped, therefore creating more durable materials. The aim of the research is to design a micro concrete with self-healing properties, based on Engineered Cementitious Composites principles from the literature and using local raw materials.


2013 ◽  
Vol 818 ◽  
pp. 124-131
Author(s):  
Assed N. Haddad ◽  
Jorge F. de Morais ◽  
Ana Catarina J. Evangelista

Nanomaterials could change the face of modern construction because they are more resistant, more durable and have notable features. Concrete is a material widely used in construction industry worldwide. Carbon nanotube has been considered a new and outstanding material in nanoscience field with great potential application in the construction industry. The study presented in this paper, aims at assessing how carbon nanotubes can affect cement composites and so the concrete, in terms of microstructure and physical-mechanical properties. Three different ratios of carbon nanotubes have been searched: 0.20%, 0.40% and 0.60%. To evaluate the mechanical properties of the samples, destructive and non-destructive tests were carried out to obtain compressive strength, tensile strength by diametrical compression, dynamic modulus of elasticity as well as the determination of their deformation properties. This work also aims to motivate entrepreneurs and professionals in the sector of civil engineering on the advantages of the application of nanotechnology in construction, as well as providing information to the scientific and technological community in general.


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