scholarly journals Engineering Properties of Self-Consolidating Lightweight Aggregate Concrete and Its Application in Prestressed Concrete Members

2018 ◽  
Vol 10 (2) ◽  
pp. 142 ◽  
Author(s):  
How-Ji Chen ◽  
Kuo-Cheng Wu ◽  
Chao-Wei Tang ◽  
Chung-Ho Huang
2016 ◽  
Vol 135 ◽  
pp. 148-157 ◽  
Author(s):  
Payam Shafigh ◽  
Mohammad A. Nomeli ◽  
U. Johnson Alengaram ◽  
Hilmi Bin Mahmud ◽  
Mohd Zamin Jumaat

2018 ◽  
Vol 8 (8) ◽  
pp. 1324 ◽  
Author(s):  
How-Ji Chen ◽  
Chung-Hao Wu

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.


2020 ◽  
Vol 8 (2) ◽  
pp. 48-56
Author(s):  
Mohammad H. Jannaty ◽  
Dawood Atrushi

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.


2012 ◽  
Vol 450-451 ◽  
pp. 338-342
Author(s):  
Ming Jie Mao ◽  
Qiu Ning Yang

A lightweight aggregate with low permeability was employed in the concrete slab; and the strength of the slab is mainly discussed. The purpose of present study is to evaluate experimentally the punching shear strength of lightweight concrete slab, and to propose the punching shear strength equation for the slab with lightweight aggregate concrete. The applicability of the proposed equation to the both reinforced concrete and pre-stressed concrete slabs with lightweight aggregate concrete.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3895
Author(s):  
Rafał Stanisław Szydłowski ◽  
Barbara Łabuzek

The paper presents the experimental results of shrinkage, creep, and prestress loss in concrete with lightweight aggregate obtained by sintering of fly ash. Two concrete mixtures with different proportions of components were tested. Concrete with a density of 1810 and 1820 kg/m3, and a 28-day strength of 56.9 and 58.4 MPa was obtained. Shrinkage and creep were tested on 150 × 250 × 1000 mm3 beams. Creep was tested under prestressing load for 539 days and concrete shrinkage for 900 days. The measurement results were compared with the calculations carried out according to the Eurocode 2 as well as with the results of other research. A very low creep coefficient and lower shrinkage in relation to the calculation results and the results of other research were found. It was also revealed that there is a clear correlation between shrinkage and creep, and the amount of water in the concrete. The value of the creep coefficient during the load holding period was 0.610 and 0.537, which is 56.0 and 49.3% of the value determined from the standard. The prestressing losses in the analyzed period amounted to an average of 13.0%. Based on the obtained test results, it was found that the tested lightweight aggregate concrete is well suited for prestressed concrete structures. Shrinkage was not greater than that calculated for normal weight concrete of a similar strength class, which will not result in increased loss of prestress. Low creep guarantees low deflection increments over time.


2012 ◽  
Vol 517 ◽  
pp. 398-402 ◽  
Author(s):  
Yan Min Yang ◽  
Hao Zhang

The use of lightweight and energy saving materials is the main trend of modern building and construction technology. All-lightweight aggregate concrete, which is a new type of lightweight aggregate concrete, not only has all the advantages of light weight concrete but also a lower apparent density of 600kg/m3. At present, the commonly-used energy-saving organic insulation materials include the EPS insulation and polyurethane insulation. The paper presents a new type of all-lightweight inorganic aggregate concrete by replacing organic material, in order to obtain a lightweight, energy-efficient building structure which synthesizes the load-bearing capacity, lightweight and energy-saving. Tests on the flexural behaviors of 11 all-lightweight aggregate concrete beams and 6 slabs were conducted. The effects of steel reinforcement ratio and loading distribution on the flexural and shear behaviors and method to calculate the load carrying capacity were carried out. The feasibility of application of all-lightweight aggregate concrete on multi-story buildings and to replace common reinforced concrete members in bending was discussed. The experimental study in the paper can provide a basis of the lightweight and energy-saving multi-story structure.


2017 ◽  
Vol 149 ◽  
pp. 976-988 ◽  
Author(s):  
Javad Nodeh Farahani ◽  
Payam Shafigh ◽  
Belal Alsubari ◽  
Sheida Shahnazar ◽  
Hilmi Bin Mahmud

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