scholarly journals Experimental Investigation of the Production of Sustainable Lightweight Concrete

2020 ◽  
Vol 38 (11A) ◽  
pp. 1652-1665
Author(s):  
Mouhammed J. Lafta
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Dry Density ◽  
Normal Concrete ◽  
Cement Ratio ◽  
Water To Cement Ratio ◽  
Concrete Production ◽  
Concrete Mix

An experimental study on four types of coarse aggregate was conducted to produce lightweight concrete. These four types are namely; white limestone, red limestone, clay brick fragments, and pumice. Ordinary Portland cement was used for all examined mixes. Water to cement ratio (w/c) was modified according to the effect of coarse aggregate type on the workability of the resulted concrete for each mix. The reference concrete mix, which is normal concrete, water to cement ratio used was (0.5). The investigated characteristics for all concrete mixes were workability, compressive strength, dry density, absorption, and thermal conductivity. Results indicated that the aggregate type significantly affects most of the properties of lightweight concrete mixes such as workability, density, and thermal insulation for all tested types of concrete. All investigated specimens indicated improvement in terms of density, workability, and thermal conductivity when compared to the reference concrete mix. Yet, it was derived from the testing results that using pumice in lightweight concrete production is the optimum option among the other examined types. When compared to normal concrete, this type of lightweight concrete showed a 41% decrease in dry density, nearly 72.54% decrease in thermal conductivity, and about 12% increase in workability. However, it is vital to notice that due to the low compressive strength and the relatively high absorption capability for all the examined types of lightweight concrete, it is suggested to use these types of concrete for non-structural walls that are not subjected to or exposed to high humidity.

scholarly journals THE RELATIONSHIPS BETWEEN COMPRESSIVE STRENGTH AND DENSITY OF POLYSTYRENE LIGHTWEIGHT CONCRETE AND THEIR COMPONENT RATIOS

2020 ◽  
pp. 1-11
Author(s):  
Mohammed Al-lami ◽  
Emad Al-saadi
Keyword(s):  
Compressive Strength ◽  
Thermal Insulation ◽  
Lightweight Concrete ◽  
Experimental Program ◽  
Dry Density ◽  
Low Density ◽  
Cement Ratio ◽  
Water To Cement Ratio ◽  
Lining Material ◽  
Mathematical Relationships

The research deals with the properties of lightweight concrete, made from polystyrene, cement, sand and water, namely the compressive strength and density. This type of lightweight concrete is characterized by thermal insulation, low density and good compressive strength compared to other types of lightweight concrete. It is used as a lining material in inclination surfaces and in the production of unloaded building units and elements. The aim of this paper is to develop mathematical relationships between compressive strength and density of concrete and their mix proportions such as sand to cement ratio (S/C), water to cement ratio (W/C) and polystyrene to cement ratio (P/C). An intensive experimental program has been conducted. From the results of the tests, a mathematical relationships were suggested to find the proportions of components based the required compressive strength and dry density.

scholarly journals Use of Recycled Tyre Rubber in Non-structural Concrete

2018 ◽  
Vol 203 ◽  
pp. 06001
Author(s):  
Muhammad Bilal Waris ◽  
Hussain Najwani ◽  
Khalifa Al-Jabri ◽  
Abdullah Al-Saidy
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Coarse Aggregate ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Structural Concrete ◽  
Cement Ratio ◽  
Mix Proportion ◽  
Water To Cement Ratio ◽  
Concrete Blocks

To manage tyre waste and conserve natural aggregate resource, this research investigates the use of waste tyre rubber as partial replacement of fine aggregates in non-structural concrete. The research used Taguchi method to study the influence of mix proportion, water-to-cement ratio and tyre rubber replacement percentage on concrete. Nine mixes were prepared with mix proportion of 1:2:4, 1:5:4 and 1:2.5:3; water-to-cement ratio of 0.25, 0.35 and 0.40 and rubber to fine aggregate replacement of 20%, 30% and 40%. Compressive strength and water absorption tests were carried out on 100 mm cubes. Compressive strength was directly proportional to the amount of coarse aggregate in the mix. Water-to-cement ratio increased the strength within the range used in the study. Strength was found to be more sensitive to the overall rubber content than the replacement ratio. Seven out of the nine mixes satisfied the minimum strength requirement for concrete blocks set by ASTM. Water absorption and density for all mixes satisfied the limits applicable for concrete blocks. The study indicates that mix proportions with fine to coarse aggregate ratio of less than 1.0 and w/c ratio around 0.40 can be used with tyre rubber replacements of up to 30 % to satisfy requirements for non-structural concrete.

scholarly journals Production of lightweight Geopolymer concrete using artificial local lightweight aggregate

2018 ◽  
Vol 162 ◽  
pp. 02024
Author(s):  
Waleed Abbas ◽  
Wasan Khalil ◽  
Ibtesam Nasser
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Experimental Tests ◽  
Pulse Velocity ◽  
Dry Density ◽  
Geopolymer Concrete

Due to the rapid depletion of natural resources, the use of waste materials and by-products from different industries of building construction has been gaining increased attention. Geopolymer concrete based on Pozzolana is a new material that does not need the presence of Portland cement as a binder. The main focus of this research is to produce lightweight geopolymer concrete (LWGPC) using artificial coarse lightweight aggregate which produced from locally available bentonite clays. In this investigation, the binder is low calcium fly ash (FA) and the alkali activator is sodium hydroxide and sodium silicate in different molarities. The experimental tests including workability, fresh density, also, the compressive strength, splitting tensile strength, flexural strength, water absorption and ultrasonic pulse velocity at the age of 7, 28 and 56 days were studied. The oven dry density and thermal conductivity at 28 days age are investigated. The results show that it is possible to produce high strength lightweight geopolymer concrete successfully used as insulated structural lightweight concrete. The 28-day compressive strength, tensile strength, flexural strength, dry density, and thermal conductivity of the produced LWGPC are 35.8 MPa, 2.6MPa, 5.5 MPa, 1835kg/m3, and 0.9567 W/ (m. K), respectively.

scholarly journals Novel Core-Shell Non-Sintered Lightweight Aggregate Concrete for Better Properties in Wallboard

2021 ◽  
Author(s):  
Chaoming PANG ◽  
Xinxin MENG ◽  
Chunpeng ZHANG ◽  
Jinlong PAN
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Insulation ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Dry Density ◽  
Core Shell ◽  
Aggregate Concrete ◽  
The Core

Abstract Shrinkage of foam concrete can easily cause cracking and thus makes it difficult for a manufacturer to maintain quality. The density of lightweight aggregate concrete is too high to meet specifications for lightweight and thermal insulation for wallboard. Two types of concrete with dry density in the range 1000–1200 kg/m3 for use in wallboard were designed and prepared using foam and lightweight aggregate. The properties of porous lightweight aggregate concrete with core-shell non-sintered lightweight aggregate were compared with sintered lightweight aggregate concrete along with several dimensions. The two aggregates were similar in particle size, density, and strength. The effects of each aggregate on the workability, compressive strength, dry shrinkage, and thermal conductivity of the lightweight concrete were analyzed and compared. Pore structures were determined by mercury intrusion porosimetry and X-ray computed tomography. Compressive strength ranged from 7.8 to 11.8 MPa, and thermal conductivity coefficients ranged from 0.193 to 0.219 W/m/K for both types of concrete. The results showed that the core-shell non-sintered lightweight aggregate bonded better with the paste matrix at the interface transition zone and had a better pore structure than the sintered lightweight aggregate concrete. Slump flow of the core-shell non-sintered lightweight aggregate concrete was about 20% greater than that of the sintered lightweight aggregate concrete, 28d compressive strength was about 10% greater, drying shrinkage was about 10% less, and thermal conductivity was less. Porous lightweight aggregate concrete using core-shell non-sintered lightweight aggregate performs well when used in wallboard because of its low density, high thermal insulation, and improved strength.

scholarly journals Resistencia de concreto con agregado de alta absorción y baja relación a/c

2012 ◽  
Vol 2 (1) ◽  
pp. 21-28
Author(s):  
R. G. Solís ◽  
E. Moreno ◽  
E. Arjona
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Construction Site ◽  
Cement Ratio ◽  
Limestone Aggregate ◽  
Concrete Mixtures ◽  
Water To Cement Ratio ◽  
Maximum Compressive Strength ◽  
Crushed Limestone ◽  
High Absorption

RESUMENLa resistencia del concreto depende de la calidad de la pasta de cemento y de las características de los agregados pétreos. La primera es controlada por la relación agua - cemento, mientras que las propiedades de los agregados generalmente no pueden ser manipuladas ya que se suele utilizar aquellos que están disponibles cerca de la construcción. En muchas regiones rocas con propiedades no deseables son utilizadas como agregado. Por lo tanto, el objetivo de este trabajo fue responder a la pregunta sobre cuál sería la máxima resistencia de diseño que se podría utilizar para concretos fabricados con un tipo específico de agregados obtenidos a partir de la trituración de roca caliza de alta absorción. Se probaron concretos con seis relaciones agua - cemento y dos tamaños de agregado grueso. Se concluyó que con los agregados estudiados es posible fabricar concretos de hasta 500 k/cm2 de f’c.Palabras clave: Absorción; agregados calizos; concreto; relación agua/cemento; resistencia.ABSTRACTConcrete strength depends on the cement paste quality and on the characteristics of the aggregates. The former is controlled by the water to cement ratio, while the properties of the aggregate, in general, cannot be manipulated as it is customary to employ the ones available near the construction site. In many regions rocks with no desirable properties are employed as aggregates. Therefore, the aim of this study was to answer the question about what would that be the maximum compressive strength attainable in concrete made with a specific type of aggregate obtained from crushed limestone of high absorption. Concrete mixtures involved six water to cement ratios and two sizes of coarse aggregate. It was concluded that with this type of aggregate it is possible to made concrete with compressive strength up to 500 k/cm2 of f’c.Key words: Absorption; compressive strength; concrete; limestone aggregate; water/cement ratio.

scholarly journals Effects of Disparate Zones of Sand on the Compressive Strength of Concrete

2021 ◽  
Vol 9 (11) ◽  
pp. 1368-1375
Author(s):  
Suhaib Bakshi
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Testing Machine ◽  
Concrete Compressive Strength ◽  
Research Papers ◽  
Concrete Material ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Concrete Mix ◽  
Compressive Strength Of Concrete

Abstract: Compressive strength of concrete is the capacity of concrete to bear loads of materials or structure sans breaking or being deformed. Specimen under compression shrinks in size whilst under tension the size elongates. Compressive strength essentially gives concept about the properties of concrete. Compressive strength relies on many aspects such as water-cement ratio, strength of cement, calidad of concrete material. Specimens are tested by compression testing machine after the span of 7 or 28 days of curing. Compressive strength of the concrete is designated by the load on the area of specimen. In this research various proportions of such aggregate mixed in preparing M 30 grade and M 40 grade of Concrete mix and the effect is studied on its compressive strength . Several research papers have been assessed to analyze the compressive strength of concrete and the effect of different zones of sand on compressive strength are discussed in this paper. Keywords: Sand, Gradation, Coarse aggregate, Compressive strength

scholarly journals Experimental Study on Light Weight Concrete Using Coconut Shell and Fly Ash

2022 ◽  
Vol 10 (1) ◽  
pp. 752-758
Author(s):  
Barkha Verma
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Fresh Concrete ◽  
Industrial Wastes ◽  
Coconut Shell ◽  
Fine Aggregate ◽  
Concrete Production ◽  
Coconut Shells

Abstract: Aggregates provide volume at low cost, comprising 66% to 78% of the concrete. With increasing concern over the excessive exploitation of natural and quality aggregates, the aggregate produced from industrial wastes and agricultural wastes is the viable new source for building material. This study was carried out to determine the possibilities of using coconut shells as aggregate in concrete. Utilizing coconut shells as aggregate in concrete production not only solves the problem of disposing of this solid waste but also helps conserve natural resources. In this paper, the physical properties of crushed coconut shell aggregate were presented. The fresh concrete properties such as the density and slump and 28 days compressive strength of lightweight concrete made with coconut shell as coarse aggregate were also presented. The findings indicate that water absorption of the coconut shell aggregate was high about 24% but crushing value and impact value were comparable to that of other lightweight aggregates. The average fresh concrete density and 28days cube compressive strength of the concrete using coconut shell aggregate 1975kg/m3 and 19.1 N/mm2 respectively. It is concluded that crushed coconut shell is suitable when it is used as a substitute for conventional aggregates in lightweight concrete production. Keywords: Coarse Aggregate, Cement, Concrete, Fly Ash, Coconut shell Aggregate, Water, Compressive Strength, Workability, Fine Aggregate.

Lightweight Concrete Precast Panels for the Improvement of Thermal Insulation of Housing with Expanded Polystyrene Beads

2021 ◽  
Vol 1033 ◽  
pp. 163-171
Author(s):  
Alexandra Reto ◽  
Renzo Sanabria ◽  
José Rodriguez ◽  
Alexandra Hinostroza
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Insulation ◽  
Lightweight Concrete ◽  
Linear Trend ◽  
Precast Concrete ◽  
Expanded Polystyrene ◽  
Dry Density ◽  
Conventional Concrete ◽  
Polystyrene Beads

The precast concrete elements in the construction of buildings are increasingly used due to their better quality control, constructive speed, reduction of the number of workers and less waste of resources compared to conventional construction; for wall applications, to these advantages, the design to ensure thermal comfort requires the improvement of the low thermal insulation of conventional concrete panels. The use of materials with lower thermal conductivity such as Expanded PolyStyrene Beads (EPSB) in lightweight concrete for the construction of precast panels in housing, contributes to improve thermal insulation and the saving operational energy during its operation phase, because the aggregate has a small size, low density and thermal conductivity; applied in higher volumes in concrete, reduces indoor heat loss in cold climates and indoor heat gain in warm climates in housing. The purpose of this research is to study the behavior of lightweight concrete with EPSB for 16%, 26% and 36% addition and evaluate the air-dry density, compressive strength, thermal conductivity, relationship between air-dry density with compressive strength and thermal conductivity. The results indicate that the higher the percentage of EPSB the air-dry density, compressive strength and thermal conductivity decrease; the relationships between air-dry density with compressive strength and thermal conductivity follow a linear trend and are similar.

Effect of Substitution of Crushed Waste Glass as Partial Replacement for Natural Fine and Coarse Aggregate in Concrete

2016 ◽  
Vol 866 ◽  
pp. 58-62 ◽  
Author(s):  
Oluwarotimi M. Olofinnade ◽  
Julius M. Ndambuki ◽  
Anthony N. Ede ◽  
David O. Olukanni
Keyword(s):  
Coarse Aggregate ◽  
Waste Glass ◽  
Glass Content ◽  
Partial Replacement ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Concrete Production ◽  
Concrete Mix

Reusing of waste glass in concrete production is among the attractive option of achieving waste reduction and preserving the natural resources from further depletion thereby protecting the environment and achieving sustainability. This present study examines the possible reuse of waste glass crushed into fine and coarse aggregate sizes as partial substitute for natural fine and coarse aggregate in concrete. The variables in this study is both the fine and coarse aggregate while the cement and water-cement ratio were held constant. The crushed glass was varied from 0 – 100% in steps of 25% by weight to replace the both the natural fine and coarse aggregate in the same concrete mix. Concrete mixes were prepared using a mix proportion of 1:2:4 (cement: fine aggregate: coarse aggregate) at water-cement ratio of 0.5 targeting a design strength of 20 MPa. Tests were carried out on total number of 90 concrete cube specimens of size 150 x 150 x150 mm and 90concrete cylinder specimens of dimension 100 mm diameter by 200 mm height after 3, 7, 14, 28, 42 and 90 days of curing. Test results indicated that the compressive and split tensile strength of the hardened concrete decreases with increasing waste glass content compared with the control. However, concrete mix made with 25% waste glass content compared significantly well with the control and can be suitably adopted for production of light weight concrete.

scholarly journals Effect of Plastic Synthetic Aggregate in the Production of Lightweight Concrete

2014 ◽  
Vol 2 (1) ◽  
pp. 83-88
Author(s):  
ELIVS M. MBADIKE ◽  
EZEOKPUBE G.C.
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Research Work ◽  
Control Test ◽  
Cement Ratio ◽  
Coarse Aggregates ◽  
Mix Proportion ◽  
Strength Tests ◽  
Average Compressive Strength

In this research work, the effect of plastic synthetic aggregate in the production of lightweight concrete was studied. The plastic synthetic aggregate was used to replace 0-40% of coarse aggregates. A mix proportion of 1:1.8:3.7 with water cement ratio of 0.47 were used. Concrete cubes of 150mmx150mmx150mm of coarse aggregate/plastic synthetic aggregate were cast and cured at 3,7,28,60 and 90 days respectively. At the end of each hydration period, the three concrete cubes for each hydration period were crushed and their average compressive strength recorded. A total of ninety (90) concrete cubes were cast. The result of the compressive strength tests for 5-40% replacement of coarse aggregates with plastic synthetic aggregate ranges from 8.07-36.71N/mm2 as against 24.58-41.21N/mm2 for the control test. The workability for 5-40% replacement of coarse aggregates with plastic synthetic aggregate ranges from 12-61mm as against 8mm for the control test (0% replacement).

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