Effect of Steel and Alkaline-Resistance Glass Fibre on Mechanical and Durability Properties of Lightweight Foamed Concrete

2012 ◽  
Vol 626 ◽  
pp. 404-410 ◽  
Author(s):  
Muhammad Hafiz Ahmad ◽  
Hanizam Awang

This paper investigates the effect of steel fibre and alkaline-resistance glass fibre lightweight foamed concrete with fly ash inclusion towards mechanical and durability properties. The lightweight foamed concrete (LFC) with a density of 1000 kg/m3with constant water sand ratio of 1: 1:5 and water cement ratio of 0.45 was cast and tested. Steel and alkaline-resistance glass fibres were used as additives and 30% of cement was replaced by fly ash. Detail experiments were setup to study the behaviour and reaction of additives which is expected to give different results on mechanical and durability properties of LFC. Compared to AR-glass fibre, steel fibre has greater contribution in terms of mechanical properties. SFLFC resulted as the most effective approach for compressive, flexural, tensile split and water absorption with strength 6.13 N/mm2, 1.96 N/mm2, 1.52 N/mm2and lowest water absorption at 6.5% respectively. On the other hand, AR-glass fibre is better in controlling drying shrinkage which leads to controlling the cracking at early age. Fly ash does not change the mechanical properties and durability due to unprocessed stage to its finer forms.

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3866
Author(s):  
Hongbo Zhang ◽  
Xiaolin Qi ◽  
Chuanyi Ma ◽  
Jianqing Wu ◽  
Yufeng Bi ◽  
...  

This paper investigates the influence of silt content and coarse particle content on the mechanical and physical properties of foamed concrete, including compressive and flexural strength, modulus of elasticity, water absorption, drying shrinkage, and air-void structure. Four types of silt with different coarse particle contents were obtained by soil mixing. The results showed that high density, low silt content, and high coarse particle content can provide better mechanical properties. High silt content and high coarse particle content would lead to lower drying shrinkage. Silt content was the main factor affecting the pore distribution of foamed concrete, and higher coarse particle content could optimize the air-void structure. Meanwhile, the change in air-void structure can accordingly affect the water absorption of foamed concrete. Results showed that, at the same density and silt content, higher coarse particle content can optimize the physical and mechanical properties of foamed concrete.


2012 ◽  
Vol 626 ◽  
pp. 594-604 ◽  
Author(s):  
Ahmad Farhan Roslan ◽  
Hanizam Awang ◽  
Md Azree Othuman Mydin

This paper presents an investigation on lightweight foamed concrete (LFC) with different type of additives. LFC with 600, 1000 and 1400 kg/m3 density were cast and tested. Fly ash, lime and polypropylene fibre were used on each density with different percentages. All the additives effects were compared with normal LFC as control mix. Mechanical properties of LFC were evaluated with several tests up to 180 days. The results show that the drying shrinkage, compressive strength and flexural strength are affected by the hydration process of each additive in the harden LFC. Fly ash as pozzolanic material helps to strengthen the LFC, though it needs longer curing period to achieve ultimate strength. Lime gives slight contribution to strength as detail investigation on microstructure formation will give clear answer on how the mechanical properties were affected. The addition of polypropylene contributes to flexural strength and shrinkage of LFC. Polypropylene fibre only contributes to compressive strength at low LFC density.


2015 ◽  
Vol 72 ◽  
pp. 54-59 ◽  
Author(s):  
Umar Adli Amran ◽  
Sarani Zakaria ◽  
Chin Hua Chia ◽  
Sharifah Nabihah Syed Jaafar ◽  
Rasidi Roslan

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6692
Author(s):  
Xianhui Zhao ◽  
Haoyu Wang ◽  
Linlin Jiang ◽  
Lingchao Meng ◽  
Boyu Zhou ◽  
...  

The long-term property development of fly ash (FA)-based geopolymer (FA−GEO) incorporating industrial solid waste carbide slag (CS) for up to 360 d is still unclear. The objective of this study was to investigate the fresh, physical, and mechanical properties and microstructures of FA−GEO composites with CS and to evaluate the effects of CS when the composites were cured for 360 d. FA−GEO composites with CS were manufactured using FA (as an aluminosilicate precursor), CS (as a calcium additive), NaOH solution (as an alkali activator), and standard sand (as a fine aggregate). The fresh property and long-term physical properties were measured, including fluidity, bulk density, porosity, and drying shrinkage. The flexural and compressive strengths at 60 d and 360 d were tested. Furthermore, the microstructures and gel products were characterized by scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The results show that the additional 20.0% CS reduces the fluidity and increases the conductivity of FA−GEO composites. Bulk densities were decreased, porosities were increased, and drying shrinkages were decreased as the CS content was increased from 0.0% to 20.0% at 360 d. Room temperature is a better curing condition to obtain a higher long-term mechanical strength. The addition of 20.0% CS is more beneficial to the improvement of long-term flexural strength and toughness at room temperature. The gel products in CS−FA−GEO with 20.0% CS are mainly determined as the mixtures of sodium aluminosilicate (N−A−S−H) gel and calcium silicate hydration (C−S−H) gel, besides the surficial pan-alkali. The research results provide an experimental basis for the reuse of CS in various scenarios.


2018 ◽  
Vol 30 (3) ◽  
Author(s):  
Chai Teck Jung ◽  
Tang Hing Kwong ◽  
Koh Heng Boon

Abstract: This paper presents some experimental results and discusses the used of recycled foamed aggregates as natural coarse aggregates replacement in producing concrete. The physical properties of recycled foamed aggregates concrete were investigated. The properties studied are water absorption and drying shrinkage from the concrete early ages until the periods of 56 days. The 100 mm x 100 mm cube specimen was used to study the water absorption at the age of 7, 28 and 56 days. Meanwhile, the 100 mm x 100 mm x 300 mm length prism had been casted and used for drying shrinkage test for recycled foamed aggregates concrete. The foamed aggregates was produced from crushing recycled foamed concrete blocks. It were coated with cement paste to reduce its water absorption ability during casting process. Superplasticizer was used to maintain the workability of fresh concrete with a slump vary between 50 mm to 100 mm. The physical tests were conducted on recycled foamed aggregates to determine their initial properties such as loose bulk density, sieve analysis and water absorption rate. Recycled foamed aggregate concretes were produced with varied water cement ratio. The results obtained indicated that the linear elastic relationship between water cement ratio and water absorption rate. The higher the water cement ratio of concrete specimen will obtained higher water absorption rate. Vice versa, the density is low for drying shrinkage. The water absorption decreased while drying shrinkage becomes more stabilized over curing period.


2020 ◽  
Vol 5 (2) ◽  
pp. 14
Author(s):  
Matthew S. Sullivan ◽  
Mi G. Chorzepa ◽  
Stephan A. Durham

Ternary blends of cementitious materials are investigated. A cement replacement level of 45% is used for all ternary mixtures consisting of 15% metakaolin and 30% slag replacements. Three metakaolin and two blast furnace slag, referred to as ‘slag’ for short, products commercially available are used to compare performance in ternary blends. A mixture with a 45% fly ash replacement is included to serve as a benchmark for performance. The control mixture contains 422 kg of cement per cubic meter of concrete, and a water-to-cementitious material ratio of 0.43 is used for all mixtures with varying dosages of superplasticizer to retain workability. Mixtures are tested for mechanical properties, durability, and volumetric stability. Mechanical properties include compression, split-cylinder tension, modulus of rupture, and dynamic Young’s modulus. Durability measures are comprised of rapid chloride-ion penetrability, sulfate resistance, and alkali–silica reactivity. Finally, the measure of dimensional stability is assessed by conducting drying shrinkage and coefficient of thermal expansion tests. Results indicate that ternary mixtures including metakaolin perform similarly to the control with respect to mechanical strength. It is concluded that ternary blends perform significantly better than both control and fly ash benchmark in tests measuring durability. Furthermore, shrinkage is reduced while the coefficients of thermal expansion are slightly higher than control and the benchmark.


2015 ◽  
Vol 75 (5) ◽  
Author(s):  
Farah A. Hadi ◽  
Hanizam Awang ◽  
Muhammed Zuhear Almulali

This paper investigates the effect of replacing different portions of cement by fine oil palm ash (FOPA). A target density of 1000 kg/m3 was used for the foamed concrete mixes. A foamed concrete mix of 1 part binder, 2 parts filler and 0.45 part of water has been used. Cement was replaced at levels of 25, 35, 45, 55 and 65% by weight of binder. The compressive strength, density, water absorption, drying shrinkage and sorptivity were tested at different ages. The mix containing 25% of fine OPA showed enhanced properties in comparison to the control mix at the age of 90 days. The mixed showed higher compressive strength, less water absorption, increased density and lesser sorptivity. However, the same mix showed higher shrinkage readings than that of the control mix. 


2019 ◽  
Vol 6 (9) ◽  
pp. 095326 ◽  
Author(s):  
Norizzati Zulkafli ◽  
Sivakumar Dhar Malingam ◽  
Siti Hajar Sheikh Md Fadzullah ◽  
Zaleha Mustafa ◽  
Kamarul Ariffin Zakaria ◽  
...  

2010 ◽  
Vol 113-116 ◽  
pp. 1013-1016 ◽  
Author(s):  
Zhi Min He ◽  
You Jun Xie ◽  
Guang Cheng Long ◽  
Jun Zhe Liu

In precast concrete elements manufacturing, steam-cured concrete incorporating 30% fly ash encountered the problem of a too low demoulding compressive strength. To resolve it, this paper developed a new steam-cured concrete (AFSC) incorporating fly ash and a chemical activator. Experiments were conducted to investigate the mechanical properties of AFSC. The corresponding mechanism was also discussed by testing the microstructure of concrete. Results indicate that the demoulding compressive strength of AFSC can meet production requirements, and compressive and flexure strength of AFSC at later ages increase well. Compared with that of ordinary steam-cured concrete, AFSC has a higher tensile strength, and the capability of AFSC to resist cracks is enhanced remarkably. At an early age, addition of the chemical activator can distinctly accelerate the extent of hydration of the fly ash cement systems, and thus the microstructure of concrete becomes denser.


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