scholarly journals Developing a Sustainable Concrete using Waste Glass and Rubber for Application in Precast Pedestrian Slabs

2021 ◽  
Vol 7 (5) ◽  
pp. 786-803
Author(s):  
Asish Seeboo ◽  
Chetanand Choollun
Keyword(s):  
Plain Concrete ◽  
Mean Value ◽  
Partial Replacement ◽  
Sustainable Concrete ◽  
Durability Properties ◽  
Static Modulus ◽  
Fine Glass ◽  
Pre Treatment ◽  
Natural Aggregates ◽  
Static Modulus Of Elasticity

In this piece of research, n attempt was made to produce a sustainable concrete with the partial replacement of both fine and coarse natural aggregates with two different non-biodegradable wastes. The selected wastes were fine glass and shredded rubber tires. Fine glass passing through 4.75 mm BS sieve was utilised for the partial replacement of fine natural aggregates. Coarse natural aggregates were partially replaced with shredded rubber passing through 20 mm sieve and retained on 6.30 mm sieve. Several mixes with varying % of fine glass but with a fixed 10 % of shredded rubber were tested. Optimum fine glass content was determined to be in the order of 20 %. The resulting concrete exhibited lower plastic and hardened densities (2040 and 2117 kg/m3 respectively) in comparison to normal plain concrete. The static modulus of elasticity was found to be 18.3 GPa (mean value), while the splitting tensile strength was 2.37 MPa. The flexural strength showed a significant increase of 20.3% compared to the control mix. The results concluded that the concrete thus produced is a viable means of disposing of such non-biodegradable wastes (rubber and glass), thus reducing the loads at landfills. This new genre of concrete was produced at a lower cost than normal concrete because of the very low pre-treatment costs of the recycled wastes used. Furthermore, the properties tend to indicate that the concrete could be applied where lower strength and high durability properties are warranted. Hence precast slabs were made from the new design concrete and were tested along a stretch of a highly trafficable pedestrian walkway on the University campus. The slabs were continuously monitored for defects such as cracks, broken corners and slabs for a period of 24 consecutive weeks. After the test period it was observed that only 4 out of the 80 precast slabs had hairline cracks. Hence concluding the enhanced durability properties of the new design concrete. Doi: 10.28991/cej-2021-03091690 Full Text: PDF

Production of Durable High Strength Flowable Mortar Reinforced With Hybrid Fibers

2018 ◽  
Vol 9 (1) ◽  
pp. 10 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli
Keyword(s):  
Silica Fume ◽  
Impact Load ◽  
Activity Index ◽  
High Strength ◽  
Steel Fibers ◽  
Partial Replacement ◽  
Hybrid Fibers ◽  
Synthetic Fibers ◽  
Static Modulus ◽  
Static Modulus Of Elasticity

This study deals with the production of durable high strength flowable mortar (HSFM). Firstly, the optimum percentage of silica fume was determined due to Pozzolanic Activity Index (P.A.I) test. Secondly, the selected mortar reinforced by different percentages of steel fibers or hybrid fibers of  steel fibers , palm fibers and synthetic fibers (Barchip) to prepare HSFM mixes. Such mixes were tested in compressive strength, splitting tensile strength, static modulus of elasticity, flexural strength, toughness indices determination, and impact load for all the mixes. Lastly, the effects of seawater exposure on the properties of HSFM have been observed. The results show that the use of 10% silica fume as a partial replacement of cement indicate the best P.A.I. On the other hand, the hybridizations of such fibers enhance the performance of HSFM mixes. In addition, the hybrid fibers reduce the permeability of HSFM leading to significance improvement against seawater exposure.

scholarly journals Effects of Steel Fibers Geometry on the Mechanical Properties of SIFCON Concrete

2020 ◽  
Vol 6 (1) ◽  
pp. 21-33 ◽  
Author(s):  
Shahad S. Khamees ◽  
Mohammed M. Kadhum ◽  
Nameer A. Alwash
Keyword(s):  
Mechanical Properties ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Partial Replacement ◽  
Fiber Volume ◽  
Fiber Network ◽  
Static Modulus ◽  
Static Modulus Of Elasticity

This research aims to shed light on the effect of steel fiber shape, length, diameter, and aspect ratio on the mechanical properties of slurry infiltration fiber reinforced concrete (SIFCON). This study comprised of casting and testing three groups of SIFCON specimens with 6% fiber volume fraction. The first group was reinforced with micro steel fiber, other reinforced by hook end steel fibers, while the last group of specimens reinforced by mixing two shape of steel fiber as hybrid fiber (3% micro steel fiber +3% hook end steel fiber). Silica fume was used as a partial replacement (10%) by weight of cement. 3.7% super plasticizer was used to make the slurry liquid enough to penetrate through the fiber network, while the w/c ratio kept constant at 0.33. It was found from the results achieved that the compressive strength, static modulus of elasticity, splitting tensile strength and toughness are extremely affected by the geometry of fibers because the network of fibers formed and their density depends on the size and shape of fibers. Where the values of micro steel fibers are far outweighing the values of hooked end fibers. It was also deduced from empiricism results that combining long and short fibers gives excellent results.

scholarly journals Influence of the type of measuring device in determining the static modulus of elasticity of concrete

2012 ◽  
Vol 5 (5) ◽  
pp. 555-575
Author(s):  
S. S. Araújo ◽  
G. N. Guimarães ◽  
A. L. B. Geyer
Keyword(s):  
Modulus Of Elasticity ◽  
Strain Measurement ◽  
Plain Concrete ◽  
Displacement Transducer ◽  
Strain Gages ◽  
Measurement Device ◽  
Measuring Device ◽  
Static Modulus ◽  
Statistical Variation ◽  
Static Modulus Of Elasticity

This paper presents a comparative analysis of the results obtained in static modulus of elasticity tests of plain concrete cylindrical specimens. The purpose of this study is to identify and evaluate the influence of several factors involved in modulus of elasticity tests such as the strain measurement device used (dial indicators, electrical surface bonded strain gages, externally fixed strain gages and linear variation displacement transducer - LVDT), the type of concrete (Class C30 and Class C60) and cylindrical specimen size (100 mm x 200 mm and 150 mm x 300 mm). The modulus tests were done in two different laboratories in the Goiânia, GO region and were performed according to code ABNT NBR 8522:2008, which describes the initial tangent modulus test, characterized by strains measured at tension values of 0.5 MPa and 30% of the ultimate load. One hundred and sixty specimens were tested with statistically satisfactory results. It was concluded that the type of strain measurement device greatly influenced the modulus of elasticity results. Tests in specimens 100 mm x 200 mm showed highest statistical variation.

scholarly journals Influence of Pozzolan, Slag and Recycled Aggregates on the Mechanical and Durability Properties of Low Cement Concrete

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4173
Author(s):  
Eliana Soldado ◽  
Ana Antunes ◽  
Hugo Costa ◽  
Ricardo do do Carmo ◽  
Eduardo Júlio
Keyword(s):  
Fly Ash ◽  
Mechanical Performance ◽  
Concrete Surface ◽  
Recycled Aggregates ◽  
Partial Replacement ◽  
Natural Pozzolans ◽  
Durability Properties ◽  
Chloride Attack ◽  
Natural Aggregates ◽  
Reduction Of Co2

The sustainability of the construction sector demands the reduction of CO2 emissions. The optimization of the amount of cement in concrete can be achieved either by partially replacing it by additions or by reducing the binder content. The present work aims at optimizing the properties of concrete used in the production of reinforced concrete poles for electrical distribution lines, combining the maximization of compactness with the partial replacement of cement by fly ash, natural pozzolans, and electric furnace slags. Natural aggregates were also partially replaced by recycled ones in mixtures with fly ash. Two types of concrete were studied: a fresh molded one with a dry consistency and a formwork molded one with a plastic consistency. The following properties were characterized: mechanical properties (flexural, tensile splitting, and compressive strengths, as well as Young’s modulus) and durability properties (capillary water absorption, water penetration depth under pressure, resistance to carbonation, chloride migration, and concrete surface resistivity). The service life of structures was estimated, taking the deterioration of reinforcement induced by concrete carbonation or chloride attack into account. Results revealed that mixtures with fly ash exhibit higher mechanical performance and mixtures with fly ash or pozzolans reveal much higher durability results than the full Portland cement-based mixtures.

scholarly journals Concrete Production Using Fine Glass Aggregates as Partial Replacement of Sand

2019 ◽  
Vol 7 (12) ◽  
pp. 428-439
Author(s):  
Samuel Cameli Fernandes ◽  
Laerte Melo Barros ◽  
Rodrigo Paz Barros ◽  
Pedro Felix Liotto ◽  
David Barbosa de Alencar
Keyword(s):  
Raw Materials ◽  
Production Costs ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Glass Waste ◽  
Waste Reuse ◽  
Concrete Production ◽  
Fine Glass ◽  
Natural Aggregates ◽  
Sand And Gravel

Waste reuse is considered an excellent alternative for sustainable development. For the World Commission on Environment and Development in Our Common Future, sustainability is "one that meets the needs of the present without compromising the ability of future generations to meet their needs." One way to provide a sustainable solution for glass would be the reuse of glass waste in the production of concrete. Glass residues when suitably crushed and sieved, to assume appropriate granulometry, may exhibit characteristics similar to natural aggregates. The use of glass waste when used in concrete manufacturing reduces production costs. The main objective of the research was to replace, as much as possible, in percentage, the quantity of sand and gravel aggregates by glass waste with the same granulometry, as a way to reduce costs, reduce the use of raw materials and reduce the quantity of wastes that were inadequately disposed of in landfills. Samples of glass waste were collected in the construction industry itself, in works and glassware companies that work with cutting and delivery of the product. Comparisons were made between concretes produced with natural and concrete aggregates produced with the substitution of 20%, 30%, 40% and 50% of the fine aggregate, all of which glass was used as a substitute. The comparative analyzes were the mechanical properties of compression strength and diametral compression traction at 7, 14, 21, 28 and 90 days.

Determining elastic properties of sedimentary strata in terms of limestone samples by laser ultrasonics

2020 ◽  
pp. 125-134
Author(s):  
I. A. Shibaev ◽  
V. A. Vinnikov ◽  
G. D. Stepanov
Keyword(s):  
Physical And Mechanical Properties ◽  
Laser Ultrasonics ◽  
Compression Tests ◽  
S Waves ◽  
Static Modulus ◽  
Enhance Efficiency ◽  
Static Modulus Of Elasticity ◽  
Static Elastic Moduli ◽  
Non Destructive ◽  
Moduli Of Elasticity

Geological engineering often uses geomechanical modeling aimed to enhance efficiency of mining or performance of structures. One of the input parameters for such models are the static elastic moduli of rocks. This article presents the studies into the physical and mechanical properties of rocks-limestone of non-metamorphic diagenesis. The precision measurements of Pand S-waves are carried out to an accuracy of 0.2% by laser ultrasonics. The static moduli of elasticity and the deformation characteristics of rocks are determined in the uniaxial compression tests by the standards of GOST 21153.2-84 and GOST 28985-91, respectively. The correlation dependence is found between the static and dynamic elasticity moduli in limestone samples. The found correlation allows drawing the conclusion that the static modulus of elasticity can be estimated in non-destructive tests, which largely simplifies preliminary diagnostics of samples in case of limited number of test core.

Mechanism of Cement Paste with Different Particle Sizes of Bottom Ash as Partial Replacement in Portland Cement

2017 ◽  
Vol 68 (10) ◽  
pp. 2367-2372 ◽  
Author(s):  
Ng Hooi Jun ◽  
Mirabela Georgiana Minciuna ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Tan Soo Jin ◽  
Andrei Victor Sandu ◽  
...  
Keyword(s):  
Portland Cement ◽  
Construction Material ◽  
Bottom Ash ◽  
High Volume ◽  
Cement Composite ◽  
Pozzolanic Reaction ◽  
High Specific Surface Area ◽  
Partial Replacement ◽  
Natural Aggregates ◽  
Pozzolanic Properties

Manufacturing of Portland cement consists of high volume of natural aggregates which depleted rapidly in today construction field. New substitutable material such as bottom ash replace and target for comparable properties with hydraulic or pozzolanic properties as Portland cement. This study investigates the replacement of different sizes of bottom ash into Portland cement by reducing the content of Portland cement and examined the mechanism between bottom ash (BA) and Portland cement. A cement composite developed by 10% replacement with 1, 7, 14, and 28 days of curing and exhibited excellent mechanical strength on day 28 (34.23 MPa) with 63 mm BA. The porous structure of BA results in lower density as the fineness particles size contains high specific surface area and consume high quantity of water. The morphology, mineralogical, and ternary phase analysis showed that pozzolanic reaction of bottom ash does not alter but complements and integrates the cement hydration process which facilitate effectively the potential of bottom ash to act as construction material.

scholarly journals Design of Concrete Made with Recycled Brick Waste and Its Environmental Performance

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 463
Author(s):  
Ivan Janotka ◽  
Pavel Martauz ◽  
Michal Bačuvčík
Keyword(s):  
Building Materials ◽  
Research Process ◽  
Added Value ◽  
Recycled Aggregate ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Type Ii ◽  
Natural Clays ◽  
Natural Aggregates ◽  
Standardized Parameters

In addition to the known uses of natural clays, less publication attention has been paid to clays returned to the production process. Industrially recovered natural clays such as bricks, tiles, sanitary ceramics, ceramic roofing tiles, etc., are applicable in building materials based on concrete as an artificial recycled aggregate or as a pozzolanic type II addition. In this way, the building products with higher added value are obtained from the originally landfilled waste. This paper details the research process of introducing concrete with recycled brick waste (RBW) up to the application output. The emphasis is placed on using a RBW brash as a partial replacement for natural aggregates and evaluating an RBW powder as a type II addition for use in concrete. A set of the results for an RBW is reported by the following: (a) an artificial RBW fine aggregate meets the required standardized parameters for use in industrially made concrete, (b) a RBW powder is suitable for use in concrete as industrially made type II addition TERRAMENT showing the same pozzolanic reactivity as a well-known and broadly used pozzolan-fly ash, and (c) such an RBW as aggregate and as powder are, therefore, suitable for the production of industrially made TRITECH Eco-designed ready-mixed concrete.

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