scholarly journals Impact of Fly Ash on Time-Dependent Properties of Agro-Waste Lightweight Aggregate Concrete

2021 ◽  
Vol 5 (6) ◽  
pp. 156
Author(s):  
Mehdi Maghfouri ◽  
Vahid Alimohammadi ◽  
Pejman Azarsa ◽  
Iman Asadi ◽  
Yashar Doroudi ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Water Absorption ◽  
Drying Shrinkage ◽  
Lightweight Aggregate ◽  
Time Dependent ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Shrinkage Crack ◽  
Concrete Mixtures

The utilization of by-products and waste materials to substitute for the natural or manufactured resources is considered as a practical way to obtain green building materials. In concrete mixtures, amongst the many available options, Fly Ash (FA) as a by-product pozzolan has been used as a partial replacement of cement. As for the aggregates, lightweight agro-waste oil palm shell (OPS) can be used as a replacement to conventional aggregate for the production of lightweight aggregate concrete. The present communication aims to investigate the impact of FA on time-dependent development properties of OPS lightweight aggregate concrete, including density, water absorption, compressive strength up to 120-days, and drying shrinkage up to the age of 365-days under standard moist curing, partially early curing, and non-curing conditions. Additionally, drying shrinkage crack development was investigated. In this study, two series of concrete mixtures with different substitution levels of OPS (0%, 50%, and 100%) and FA were tested. From the obtained results, it was concluded that the incorporation of fly ash in OPS concrete reduces the density and compressive strength values. Dually, the initial and final water absorption values plus the rate of drying shrinkage at early and long-term ages increased. On top of that, a high potential of drying shrinkage crack, especially for mixtures with 100% OPS, was identified.

Development of Lightweight Aggregate Concrete Containing Pulverized Fly Ash and Bottom Ash

2008 ◽  
Vol 400-402 ◽  
pp. 379-384 ◽  
Author(s):  
Theradej Litsomboon ◽  
Pichai Nimityongskul ◽  
Naveed Anwar
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Apparent Density ◽  
Abrasion Resistance ◽  
Bottom Ash ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Lightweight Materials ◽  
Aggregate Concrete ◽  
Compressive Strength Of Concrete

This study examines the feasibility of using different lightweight aggregates (LA) and bottom ash as coarse and fine aggregates in concrete with fly ash. The lightweight materials were composed of 3 types, namely pumice, cellular lightweight aggregate and MTEC lightweight aggregate. The tests for physical and mechanical properties of lightweight aggregate concretes (LWAC) were conducted in terms of workability, compressive strength, apparent density, abrasion resistance and absorption. Test results showed that compressive strength of LWAC increased with an increase in apparent density, which is mainly depending on the type of aggregate. The replacement of normal weight sand with bottom ash resulted in a decrease both in density of concrete by 180-225 kg/m3 and 28-day compressive strength of concrete by 16-26%. Moreover, the use of bottom ash to replace sand in concrete increased the demand for mixing water due to its porosity and shape and to further obtain the required workability. The type and absorption of LA influenced predominantly the water absorption of LWAC. Total replacement of natural sand by bottom ash increased the absorption of the concrete by 63-90%. With regard to abrasion resistance, the abrasion resistance of lightweight aggregate concrete was mainly dependent on the compressive strength of concrete: the higher the strength, the higher the abrasion resistance of LWAC. In addition, the use of bottom ash as a fine aggregate resulted in a lower abrasion resistance of lightweight aggregate concrete due to its porosity. Of the three types of lightweight materials, MTEC LA had achieved both low density and high compressive strength.

The Effects of Cement Content, Sand Percentage and Fly Ash Dosage on Lightweight Aggregate Concrete

2006 ◽  
Vol 302-303 ◽  
pp. 282-287
Author(s):  
Liu Wei ◽  
Feng Xing ◽  
Lu Han
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Strength Class ◽  
Cement Content ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Ongoing Research ◽  
Aggregate Concrete ◽  
Structural Lightweight Aggregate Concrete

The paper is one part of ongoing research on structural lightweight aggregate concrete. Lightweight aggregate concrete with compressive strength class of CL40 and slump of 160-200 mm were studied. The influences of the cement content, sand percentage and fly ash dosage on properties of fresh and hardened LWAC, such as fresh density, workability and compressive strength were investigated.

scholarly journals Mechanical Properties of Chopped Basalt Fiber-Reinforced Lightweight Aggregate Concrete and Chopped Polyacrylonitrile Fiber Reinforced Lightweight Aggregate Concrete

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1715 ◽  
Author(s):  
Yusheng Zeng ◽  
Xianyu Zhou ◽  
Aiping Tang ◽  
Peng Sun
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Shear Strength ◽  
Water Absorption ◽  
Basalt Fiber ◽  
Lightweight Aggregate ◽  
Splitting Tensile Strength ◽  
Lightweight Aggregate Concrete ◽  
Polyacrylonitrile Fiber ◽  
Aggregate Concrete

In this study, an experimental investigation was conducted on the mechanical properties of lightweight aggregate concrete (LWAC) with different chopped fibers, including basalt fiber (BF) and polyacrylonitrile fiber (PANF). The LWAC performance was studied in regard to compressive strength, splitting tensile strength and shear strength at age of 28 days. In addition, the oven-dried density and water absorption were measured as well to confirm whether the specimens match the requirement of standard. In total, seven different mixture groups were designed and approximately 104 LWAC samples were tested. The test results showed that the oven-dried densities of the LWAC mixtures were in range of 1.819–1.844 t/m3 which satisfied the definition of LWAC by Chinese Standard. Additionally, water absorption decreased with the increasing of fiber content. The development tendency of the specific strength of LWAC was the same as that of the cube compressive strength. The addition of fibers had a significant effect on reducing water absorption. Adding BF and PANF into concrete had a relatively slight impact on the compressive strength but had an obvious effect on splitting tensile strength, flexural strength and shear strength enhancement, respectively. In that regard, a 1.5% fiber volume fraction of BF and PANF showed the maximum increase in strength. The use of BF and PANF could change the failure morphologies of splitting tensile and flexural destruction but almost had slight impact on the shear failure morphology. The strength enhancement parameter β was proposed to quantify the improvement effect of fibers on cube compressive strength, splitting tensile strength, flexural strength and shear strength, respectively. And the calculation results showed good agreement with test value.

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 Properties of oil palm shell lightweight aggregate concrete containing fly ash as partial cement replacement

2020 ◽  
Vol 849 ◽  
pp. 012048
Author(s):  
Khairunisa Muthusamy ◽  
Mohamad Safwan Jaafar ◽  
Nili Wahida Azhar ◽  
Nurazzimah Zamri ◽  
Nadiah Samsuddin ◽  
...  
Keyword(s):  
Fly Ash ◽  
Oil Palm ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Cement Replacement ◽  
Palm Shell ◽  
Oil Palm Shell ◽  
Partial Cement Replacement

scholarly journals Size Effect in Compressive Strength Tests of Cored Specimens of Lightweight Aggregate Concrete

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1187 ◽  
Author(s):  
Lucyna Domagała
Keyword(s):  
Compressive Strength ◽  
Scale Effect ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Cement Matrix ◽  
Lightweight Aggregate Concrete ◽  
Core Diameter ◽  
Aggregate Concrete ◽  
Normal Weight Concrete ◽  
Strength Tests

The aim of this paper is to discuss the unrecognized problem of the scale effect in compressive strength tests determined for cored specimens of lightweight aggregate concrete (LWAC) against the background of available data on the effect for normal-weight concrete (NWAC). The scale effect was analyzed taking into consideration the influence of slenderness (λ = 1.0, 1.5, 2.0) and diameter (d = 80, 100, 125, and 150 mm) of cored specimens, as well as the type of lightweight aggregate (expanded clay and sintered fly ash) and the type of cement matrix (w/c = 0.55 and 0.37). The analysis of the results for four lightweight aggregate concretes revealed no scale effect in compressive strength tests determined on cored specimens. Neither the slenderness, nor the core diameter seemed to affect the strength results. This fact should be explained by the considerably better structural homogeneity of the tested lightweight concretes in comparison to normal-weight ones. Nevertheless, there were clear differences between the results obtained on molded and cored specimens of the same shape and size.

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