scholarly journals Assessment of Curing Exposures Effect on the Long-term Engineering Properties of Novel Lightweight Aggregate Concrete

2020 ◽  
Vol 8 (2) ◽  
pp. 48-56
Author(s):  
Mohammad H. Jannaty ◽  
Dawood Atrushi
Keyword(s):  
Lightweight Aggregate ◽  
Developed Countries ◽  
Expanded Polystyrene ◽  
Engineering Properties ◽  
Lightweight Aggregate Concrete ◽  
Dry Density ◽  
Aggregate Concrete ◽  
Curing Conditions ◽  
Recycling Technique

At present, most of the generated waste expanded polystyrene (EPS) in developed countries are transported to landfill and in some developing and/or less-developed countries such as Iraq are sent to open landscapes; consequently, this inadequate waste disposal can be very dangerous to our health and environment. This study describes engineering properties of sustainable lightweight aggregate concrete (LWAC) incorporating novel aggregates of waste EPS produced by a unique recycling technique of densifying. The new recycling technique significantly improved the segregation resistance of EPS beads in concrete as these beads are ultra-light material. The novel LWA of densified EPS (DEPS) was used as partial natural aggregate replacement in the mixes. Three water/cement (W/C) ratios were used. Three different types of curing conditions of indoor full water curing, outdoor weathering exposure, and heating exposure were employed during this study to represent different conditions which concrete may be subject to. The engineering properties of concrete investigated were consistency, dry density, compressive strength, and ultrasonic pulse velocity (UPV) for long-term performance of more than one-year age. It was indicated that the properties of concrete were not only primarily influenced by the employed curing conditions but the content of DEPS in the mixtures and additionally the W/C ratio had effect on the properties of concrete. However, adequate engineering properties can be achieved using an appropriate amount of DEPS with proper W/C and curing conditions.

Engineering properties of lightweight aggregate concrete containing limestone powder and high volume fly ash

2016 ◽  
Vol 135 ◽  
pp. 148-157 ◽  
Author(s):  
Payam Shafigh ◽  
Mohammad A. Nomeli ◽  
U. Johnson Alengaram ◽  
Hilmi Bin Mahmud ◽  
Mohd Zamin Jumaat
Keyword(s):  
Fly Ash ◽  
Lightweight Aggregate ◽  
High Volume ◽  
Limestone Powder ◽  
Engineering Properties ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
High Volume Fly Ash

scholarly journals Influence of Aggregate Gradation on the Engineering Properties of Lightweight Aggregate Concrete

2018 ◽  
Vol 8 (8) ◽  
pp. 1324 ◽  
Author(s):  
How-Ji Chen ◽  
Chung-Hao Wu
Keyword(s):  
Compressive Strength ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Engineering Properties ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Gradation ◽  
Aggregate Concrete ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Expanded Shale

Expanded shale lightweight aggregates, as the coarse aggregates, were used to produce lightweight aggregate concrete (LWAC) in this research. At the fixed water-cement ratio, paste quantity, and aggregate volume, the effects of various aggregate gradations on the engineering properties of LWAC were investigated. Comparisons to normal-weight concrete (NWC) made under the same conditions were carried out. From the experimental results, using normal weight aggregates that follow the specification requirements (standard gradation) obtained similar NWC compressive strength to that using uniform-sized aggregates. However, the compressive strength of LWAC made using small uniform-sized aggregates was superior to that made from standard-grade aggregates. This is especially conspicuous under the low water-cement ratio. Even though the workability was affected, this problem could be overcome with developed chemical additive technology. The durability properties of concrete were approximately equal. Therefore, it is suggested that the aggregate gradation requirement of LWAC should be distinct from that of NWC. In high strength LWAC proportioning, following the standard gradation suggested by American Society for Testing and Materials (ASTM) is optional.

scholarly journals THE EFFECT OF EXPANDED GLASS AND POLYSTYRENE WASTE ON THE PROPERTIES OF LIGHTWEIGHT AGGREGATE CONCRETE

2016 ◽  
Vol 8 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Jurga Šeputytė-Jucikė ◽  
Marijonas Sinica
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Conductivity Coefficient ◽  
Lightweight Aggregate ◽  
Expanded Polystyrene ◽  
Partial Replacement ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Low Thermal Conductivity ◽  
Polystyrene Waste

The main objective of this study is to create a lightweight aggregate concrete (LWAC) with a low thermal conductivity coefficient using expanded glass (EG) aggregate, produced from waste glass or crushed expanded polystyrene waste, obtained by crushing waste packing tare of household appliances. Research related to the effects of the amount of Portland cement (PC) as well as EG aggregates and crushed expanded polystyrene waste on physical (density, thermal conductivity coefficient, water absorption and capillary coefficient) and mechanical (compressive strength) properties of LWAC samples are provided. Insulating LWAC based on a small amount of PC and lightweight EG aggregates and crushed expanded polystyrene waste, with especially low thermal conductivity coefficient values (from 0.070 to 0.098 W/ (m·K)) has been developed. A strong relationship between thermal conductivity coefficient and density of LWAC samples was obtained. The density of LWAC samples depending on the amount of PC ranged between 225 and 335 kg/m3. A partial replacement of EG aggregate by crushed expanded polystyrene waste, results in relative density decrease of LWAC samples. In LWAC samples the increased amount of PC results in increased compressive strength.

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.

Prediction of the long-term durability of lightweight aggregate concrete mixtures under severe marine environment

2006 ◽  
Vol 39 (9) ◽  
pp. 911-918 ◽  
Author(s):  
Yannick Maltais ◽  
Eric Ouellet ◽  
Jacques Marchand ◽  
Eric Samson ◽  
Douglas Burke
Keyword(s):  
Marine Environment ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Concrete Mixtures

scholarly journals The Structural Characteristics of Lightweight Aggregate Concrete Beams

2019 ◽  
Vol 27 (2) ◽  
pp. 64-73
Author(s):  
Sajjad abdulameer Badar ◽  
Laith Shakir Rasheed ◽  
Shakir Ahmed Salih
Keyword(s):  
Compressive Strength ◽  
Ultimate Load ◽  
Lightweight Concrete ◽  
Concrete Beams ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Lightweight Aggregate Concrete ◽  
Dry Density ◽  
Aggregate Concrete ◽  
Clay Bricks

This paper aims to investigate the structural behavior of reinforced lightweight concrete beams. Attapulgite aggregate and crushed clay brick aggregate were used as coarse lightweight aggregate to produce structural lightweight aggregate concrete with 25 Mpa and 43.6 Mpa cube compressive strength and 1805 Kg/m3 and 1977 Kg/m3 oven dry density respectively. The result of reinforced lightweight concrete beams compared with reinforced normal weight concrete beams, which have 50.5 Mpa cylinder compressive strength and 2317 Kg/m3 oven dry density. For each type of concrete two reinforced concrete beams with (1200 mm length × 180 mm height × 140 mm width), one of them tested under symmetrical two-points load STPL (a/d = 2.2) and another one tested under one-point load OPL (a/d=3.3) at 28 days. The experimental program shows that a structural lightweight aggregate concrete can be produced by using Attapulgite aggregate with 25 MPa cube compressive strength and 1805 Kg/m3 oven dry density and by using crushed clay brick aggregate with 43.6 MPa cube compressive strength and 1977 Kg/m3 oven dry density. The weight of Attapulgite aggregate concrete and crushed clay bricks aggregate concrete beam specimens were lower than normal weight aggregate concrete beams by about 20.56% and 13.65% respectively at 28 days.  As for the ultimate load capacities of beam specimens, the ultimate load of Attapulgite aggregate concrete beams tested under STPL were lower than that of crushed clay bricks aggregate concrete beams and normal weight aggregate concrete beams by about 4.85% and 5% respectively. While the ultimate load capacities of reinforced Attapulgite concrete beams tested under OPL were lower than that of reinforced crushed clay bricks aggregate concrete beams and reinforced normal weight aggregate concrete beams by about 10.3% and 10.5% respectively. Finally, Attapulgite aggregate concrete and crushed clay bricks aggregate concrete showed ductility and toughness less than that of Normal weight aggregate concrete.

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