Lightweight Foamed Concrete Research Articles

Mechanical Properties of Low Densities Lightweight Foamed Concrete Strengthen with Raw Empty Fruit Bunch Fibre

Mechanical Properties of Low Densities Lightweight Foamed Concrete Strengthen with Raw Empty Fruit Bunch Fibre

Experimental and numerical investigation of lightweight foamed reinforced concrete deep beams with steel fibers

This paper aims to experimentally and numerically study the effect of steel fiber on the behavior of Lightweight Foamed Reinforced Concrete (LWFRC) deep beams and its mechanism to improve the mechanical properties and crack control of concrete. In addition to this, steel fibers compensate for the lack of resistance due to the use of lightweight foamed concrete (LWFC). This paper will also address the effect of some variable parameters on the structural behavior such as: (1) volume of fiber; (2) fiber aspect ratio; (3) longitudinal reinforcement ratio.The experimental program consists of four groups; each group comprises two beams compared to the control specimen. All beams have an overall depth of 800 mm, width of 150 mm, and total length of 2200 mm with span of 2000 mm. Tests were performed under two points load with constant shear-span to depth ratio equal to one. The used LWFC has an average cubic, cylindrical compressive strength and splitting tensile strength of 33, 28 and 3.10 MPa, respectively. Hooked end steel fibers with length 40, 50, and 60 mm and 0.8 mm diameter were used with 0%, 0.5%, 0.75% and 1.0% volumetric ratio.The obtained results indicated that the cracking and the ultimate load has increased by 18.5% and 25.5%, respectively due to use steel fibers. Furthermore, the displacement ductility and toughness has increased by 38% and 56%, respectively. The failure mode of LWFRC deep beams is shear brittle failure.Shear capacity of all deep beams based on ECP 203–2017 (ECP-203, 2017) is calculated and compared with that from ACI 318–19 (ACI 318-19, 2018) which is based on strut and tie model (STM). Comparing the experimental results with STM results showed that ECP 203–2017 (ECP-203, 201) is slightly conservative in calculating the ultimate capacity than ACI 318–19 (ACI 318-19, 2018) for the range of the studied variables in this research and not in general. Finally, as the STMs are debatable, ANSYS 15 software was used to numerically study the behavior of LWFRC deep beams. Verification of numerical models has been done by comparing the results of the load deflection curves, cracks and ultimate loads with the experimental ones.

Influence of Density, Porosity and Void Size on Thermal Conductivity of Green Lightweight Foamed Concrete

One of the methods to reduce the energy content of buildings is through selection of building materials. Strain on conventional energy can be reduced by employment of low energy materials and efficient structural design. The selection of materials also helps to capitalize on indoor comfort. For instant, the use of materials and components with small embodied energy or low thermal conductivity has enhanced the indoor comfort in building. Thus, a high level of insulation in any new material development is an essential step to an energy efficient design. The main purpose of this study is to investigate the thermal conductivity of green lightweight foamed concrete samples ranging from 650 until 1050 kg/m3 with constant cement-sand ratio of 1:1.5 and water-cement ratio of 0.5. This study was limited to the influence of density, porosity and void size on thermal conductivity of lightweight foamed concrete. Lower density foamed concrete translates to lower thermal conductivity. The density of foamed concrete is controlled by the porosity where lower density lightweight foamed concrete indicates greater porosity. Hence, thermal conductivity changes considerably with the porosity of lightweight foamed concrete because air is the poorest conductor compared to solid and liquid due to its molecular structure.

Dimensional Stability of Lightweight Foamed Concrete Containing Eggshell Powder and Calcium stearate

In order to reduce eggshell (ES) waste and reduce utilization of pure cement, various researches were conducted to study effects of eggshell powder (ESP) on properties of concrete when it partially replaces ordinary Portland cement (OPC). Dimensional stability is one of the properties that related to cracking issue and soundness of concrete, and it is generally guided by movement of moisture. This study was conducted to study the dimensional stability of lightweight foamed concrete(LFC) that containing eggshell powder and calcium stearate (CS), where, replacement level (RL) of eggshell powder ranged from 0% to 10% at interval of 2.5%, and additional of 1% calcium stearate as cement mass applied for the mixture containing 0% and 5% eggshell powder. Besides, sorptivity and initial surface absorption were tested to compare with dimensional changes, and compressive strength was tested to confirm the additives have no significant adverse effect on the strength. The result shows that incorporation of 5% eggshell powder improves sorptivity, initial surface absorption, and dimensional stability (outdoor R² value) of the lightweight foamed concrete by 33%, 55%, and 1.5% respectively, meanwhile, additional of 1% calcium stearate improves theseproperties by average 79%, 78%, and 7.2% respectively.

Dimensional Stability of Lightweight Foamed Concrete Containing Eggshell Powder and Calcium Stearate

In order to reduce eggshell (ES) waste and reduce utilization of pure cement, various researches were conducted to study effects of eggshell powder (ESP) on properties of concrete when it partially replaces ordinary Portland cement (OPC). Dimensional stability is one of the properties that related to cracking issue and soundness of concrete, and it is generally guided by movement of moisture. This study was conducted to study the dimensional stability of lightweight foamed concrete(LFC) that containing eggshell powder and calcium stearate (CS), where, replacement level (RL) of eggshell powder ranged from 0% to 10% at interval of 2.5%, and additional of 1% calcium stearate as cement mass applied for the mixture containing 0% and 5% eggshell powder. Besides, sorptivity and initial surface absorption were tested to compare with dimensional changes, and compressive strength was tested to confirm the additives have no significant adverse effect on the strength. The result shows that incorporation of 5% eggshell powder improves sorptivity, initial surface absorption, and dimensional stability (outdoor R² value) of the lightweight foamed concrete by 33%, 55%, and 1.5% respectively, meanwhile, additional of 1% calcium stearate improves theseproperties by average 79%, 78%, and 7.2% respectively.

Investigating the Effect of Sisal Fibre Content on Durability Properties of Lightweight Foamed Concrete

Investigating the Effect of Sisal Fibre Content on Durability Properties of Lightweight Foamed Concrete

Mechanical Properties of Lightweight Foamed Concrete With Ceramic Tile Wastes as Partial Cement Replacement Material

The production of concrete emits greenhouse gases which aggravate global warming. Meanwhile, ceramic tile wastes generated from manufacturing factories, construction sites, and building demolition projects disposed of by landfills create land and water pollution. Therefore, in this study, the suitability of ceramic tile wastes (CTW) in powder form to partially replace cement in lightweight foamed concrete was investigated with the aim to discover a greener construction material. Once the research outputs show that the ceramic tile dust can appropriately serve as a replacement, environmental impact on air, land, and water pollution can all be reduced. Three types of lightweight foamed concrete with 0%, 25%, and 50% ceramic tile wastes as partial cement replacement material were prepared with a target density of 1,200 kg/m3, namely, LFC-CTW0, LFC-CTW25, and LFC-CTW50, respectively. The effects of ceramic tile wastes on the engineering properties of lightweight foamed concrete were investigated. Concrete specimens were water-cured and tested for various mechanical properties at the concrete ages of 7, 28, and 56 days. Results from the lab experiments showed that the incorporation of 25% ceramic tile wastes into lightweight foamed concrete was more feasible than that of 50%. LFC-CTW25, which performed better than LFC-CTW0 for the splitting tensile strength test at day 56. The results for the compressive strength test, modulus of elasticity, and compressive toughness test showed a minor reduction after the incorporation of ceramic tile wastes. Based on the results, it can be concluded that it is feasible to use ceramic tile wastes up to 25% as partial cement replacement material to produce foamed concrete.

The Use of Fuzzy Linear Regression with Trapezoidal Fuzzy Numbers to Predict the Compressive Strength of Lightweight Foamed Concrete

The Use of Fuzzy Linear Regression with Trapezoidal Fuzzy Numbers to Predict the Compressive Strength of Lightweight Foamed Concrete

Strength Properties of Lightweight Foamed Concrete with the Presence of Additives

Strength Properties of Lightweight Foamed Concrete with the Presence of Additives

Stimulus of Raw Oil Palm Trunk (OPT) Fibre on Durability Properties of Lightweight Foamed Concrete

Lightweight Foamed Concrete (LFC) has gained a huge amount of attention because of its high flowability, low self-weight, lower use of aggregate, low strength, and its thermal insulation. Furthermore, LFC is an environmentally friendly material because of its minimal usage of aggregate and high potential to incorporate waste material such as fibre. This research was conducted to assess the potential utilisation of oil palm trunk (OPT) fibre strengthened LFC in terms of its durability. Two densities of 600kg/m3 and 1200kg/m3, were cast and tested with 4 different percentages of OPT fibre, which were 0.15%, 0.30%, 0.45% and 0.60%. The parameters evaluated were water absorption, porosity, drying shrinkage, ultrasonic pulse velocity. The results revealed that the inclusion of OPT in LFC helps to minimise water absorption and the porosity of LFC. Moreover, the inclusion of OPT also enhances the drying shrinkage and ultrasonic pulse velocity of LFC.

Lightweight foam concrete containing expanded perlite and glass sand: Physico-mechanical, durability, and insulation properties

Foam concrete refers to a type of concrete with high porosity that can be produced with or without aggregate. Foam concrete has generally superior thermal insulation properties compared to conventional concrete. Despite its major thermal benefits, the high content of Portland cement, as well as its very high porosity, makes foam concrete prone to physico-durability concerns such as drying shrinkage by allowing the entrance of chemicals and free water to the concrete pores. To address this and reduce the pore network connectivity, in this study, expanded perlite and fine-sized waste glass sand were used as the main aggregates in concrete mixes. In that respect, 10 mixes of foam concrete were produced with two foam contents of 50 and 100 kg/m3, with a constant water-to-binder ratio (w/b) of 0.5. In each mix, the dominated expanded perlite aggregate was replaced by waste glass sand having a size of < 2.36 mm. Apparent porosity, water absorption, compressive and flexural strength, sorptivity, ultrasonic pulse velocity (UPV), drying shrinkage, freeze–thaw, alkali-silica reaction, thermal conductivity, and thermal resistance tests were performed to investigate the physico-mechanical, durability and insulation properties of the foam concrete. Based on the results, it is found that the addition of glass sand improves physico-mechanical and durability properties of foam concrete. The addition of expanded perlite increases the insulating properties of foam concrete, potentially due to the high porosity of expanded perlite compared to that of glass sand. The findings of this study point to the suitability of producing sustainable insulating foam concrete through the use of waste glass sand.

An investigation on the performance of 1200 kg/m3 lightweight foamed concrete incorporated with calcium stearate

Lightweight foamed concrete (LFC) is normally used on the exterior of buildings such as walls and roof slabs, which causes it to be often exposed to natural weathering such as rain. Since water is an agent of deterioration towards the durability of LFC in long term, calcium stearate, is introduced into LFC. Calcium stearate (CS) is a type of water repellent agent that reduces the penetration of water into LFC. This research aims to investigate the effect of incorporating CS into the LFC mix in terms of its strength performance. Four types of LFC containing different percentages of CS ranging from 0 % to 0.6 % of cement weight were cast and water cured for 7, 28 and 56 days before being tested for its strength properties. It was found that adding CS into the LFC does not affect the workability of fresh concrete. The finding also showed that CS only retards the strength development rate of LFC during the early ages of LFC instead of reducing its overall strength. Under continuous curing, LFC with CS can achieve strength similar to the strength obtained by the control mix. If the early strength of LFC is not a major concern, incorporating CS into LFC will have an added advantage of lower water absorption which improves the durability of LFC.

Strength properties of renewable bio-based lightweight foam concrete incorporating of polypropylene fibre

This paper investigates the incorporating of renewable lightweight bio-based aggregate (RLWBBA) in lightweight foam concrete (LWFC). The aim of this research is to incorporate different volume fraction (Vf) of polypropylene (PP) fibre into LWFC to determine the optimum compressive strength and splitting tensile strength. Four different mix was designed containing different percentage of PP replacement (0, 0.1, 0.2 and 0.3%). From the results, the compressive strength of the oil palm shell lightweight foamed concrete with 0.3% of macro polypropylene fibre (OPSLWFC/0.3) had showed the highest compressive strength and splitting tensile strength at 28 days, which are recorded at 4.01 MPa and 0.62 MPa respectively. It also showed the lowest density among all the mix design which is 1152 kg/m3 under demoulded condition. The OPSLWFC/0.3 has increased about 23.38% of 28 days compressive strength and 37.78% of splitting tensile strength compared to the control mix, which contains 0% of fibre proportion. Hence, the findings of this research revealed that the development of environmentally friendly lightweight foamed concrete can be used as an alternative solution for traditional lightweight concrete.

Study on the performance of GFRP strengthened, fiber reinforced lightweight foam concrete

Regular clay bricks and concrete blocks are replaced with light-weight fibre-reinforced foam concrete modules. For light weight foam concrete, various natural and synthetic fibes are employed as micro- and macro-fibre reinforcement. Three distinct fibres were used as fibre reinforcement in this study, and their strength qualities were investigated. As microfibre reinforcement, synthetic-polypropylene fibre, natural-Jute fibre, and banana micro fibres were used at volume fractions ranging from 0.22 to 0.55 percent in the foam concrete mix. The compression behaviour of stack bonded masonry prisms was investigated in the first phase of the experiment. The second phase of research focused on the microfibre-reinforced prism, which was reinforced with multiple layers of GFRP sheets. Both jute and banana fibres added as microfiber reinforcement to the matrix, impart ductility to the brittle masonry unit and reduce the sudden failure mode of the Fibre-Reinforced Lightweight Foam Concrete (FRLWC) prism. The insertion of GFRP sheets between the masonry layers provides additional stiffness and ductility to the FRLWC masonry prism, which greatly improves the post-cracking behaviour. When compared to a standard LWC prism, failure patterns show that both synthetic and natural fibre-reinforcement provide improved fracture bridging mechanisms, which is mostly owing to the arresting of cracks by micro polypropylene, jute, and banana fibres. The GFRP layers provided between the masonry units prevented the formation of major crack planes.

FRESH STATE AND MECHANICAL PROPERTIES OF ULTRA-LIGHTWEIGHT FOAMED CONCRETE INCORPORATING ALKALI TREATED BANANA FIBRE

For a Lightweight Foamed Concrete (LFC) to efficiently function as an energy-saving building material, its self-weight (density) should be reduced. However, the problem associated with a reduced density is a decline in strength. To improve the mechanical properties of LFC, this research attempts to integrate banana fibre into LFC composite with a focus on fresh and harden state properties. An Ultra-Lightweight Foamed Concrete (ULFC) with a density of 600 kg/m3 was produced with the inclusion of treated and untreated banana fibres. The volume fractions of banana fibre added into LFC were 0.00% (control specimen), 0.25%, 0.35%, 0.45% and 0.55%. In addition, an optimised batch mix of ULFC reinforced with 0.35% untreated banana fibre was produced. The batches were tested for rheological, physical, and mechanical properties. Findings reveal that the workability of ULFC composites decrease with increase in fibre addition. The compressive, flexural, and tensile strengths of the alkali-treated composites were higher than the untreated banana fibre composite. SEM micrograph reveals that defibrillation of bundle fibrils due to cleaning the surface amorphous hemicellulose, lignin and pectin of the alkali-treated fibre, leads to rough surfaces and increase surface area resulting in better interfacial adhesion of the fibre with cement matrix.

Fire resistance of lightweight foam concrete by incorporating lightweight bio-based aggregate

Concrete is widely used in the industry due to its effectiveness in terms of cost and strength. In this study, the introduction of bio-based aggregate as coarse aggregate in lightweight foam concrete will be investigated to find a better solution for fire incidents that are commonly happened. As such, lightweight foam concrete (LWFC) has been applied in many buildings especially in non-load bearing wall to enhance thermal conductivity, sound insulation and fire resistance. The aim of this research is to investigate the effect of incorporating bio-based aggregate namely oil palm shell (OPS) into lightweight form concrete in terms of strength properties and fire resistance. Three different concrete mix was designed containing different percentage of OPS aggregate replacement (0, 5, 10 and 15%). From the result, the compressive strength of the LWFC-CTR mixture had achieved the highest compressive strength at 28-day, which is recorded at 3.82 MPa. The fire resistance of LWFC-OPS 15% had showed a positive outcome with improvement by almost 23.5% compared to control mix at 15 minutes. Therefore, the major finding of this research is the incorporation of eco-friendly OPS aggregate has improved the fire resistance of lightweight foam concrete, which can be used as an alternative solution for non-load bearing walls.

Mechanical Properties of Lightweight Foamed Concrete Reinforced with Raw Mesocarp Fibre

Lightweight foamed concrete (LFC) is recognised for its high flowability, minimal utilization of aggregates and superior heat insulation properties. LFC is excellent under compression but poor in tensile stress, as it produces multiple microcracks. LFC cannot withstand the tensile stress induced by applied forces without additional reinforcing elements. Hence, this study was conducted to examine the potential utilisation of oil palm mesocarp fibre (OPMF) reinforced LFC in terms of its mechanical properties. Two densities, 600kg/m3 and 1200kg/m3, were cast and tested with six different percentages of OPMF, which were 0.15%, 0.30%, 0.45% and 0.60%. The parameters evaluated were compressive strength, flexural strength and tensile strength. The results revealed that the inclusion of 0.45% of OPMF in LFC helps to give the best results for the compressive strength, flexural strength and splitting tensile strength. The OPMF facilitated to evade the promulgation of cracks in the plastic state in the cement matrix when the load was applied

Production of Light Weight Foam Concrete with Sustainable Materials

Most of the recent works related to the construction industry in Iraq are focused on investigating the validity of local raw materials as alternatives to the imported materials necessary for some practical applications, especially in thermal and sound insulation. This investigation includes the use of limestone dust as partial substitution of cement in combination with foam agent and silica fume to produce sustainable Lightweight Foam Concrete (LWFC). This study consists of two stages. In the first stage, trial mixes were performed to find the optimum dosage of foam agent. Limestone dust was used as a partial replacement for cement. Chemical analysis and fineness showed great similarity with cement. Many concrete mixes were prepared with the content of lime dust powder being 10%, 14%, and 18% as partial replacement of cement by weight. The results indicate that the compressive strength at 7, 28, and 90 days of age was increased for specimens with 14% limestone dust. The best results in compressive strength show an increase at 7 days and a decrease at 28 and 90 days for concrete specimens with 14% limestone dust. In addition, the results show a decrease in dry density for concrete containing 14% lime dust. In the second stage, different percentages of Polypropylene Fibers were added to the concrete, all mixes, containing a constant content of limestone dust of 14% by weight of cement, were modified using different percentages of Polypropylene Fibers (1%, 1.5 %, and 2% by volume) and the best percentage was found to be 1%. The addition of Polypropylene Fibers enhances splitting tensile and flexural strength at 28 days by 14.55% and 55% respectively.

INFLUENCE OF OIL PALM SPIKELETS FIBRE ON MECHANICAL PROPERTIES OF LIGHTWEIGHT FOAMED CONCRETE

As issues related to sustainable construction in Malaysia gains more importance, research on the utilization of waste by products especially from oil palm in concrete is vigorously implemented. Utilization of different parts of oil palm fibres in lightweight foamed concrete have garnered positive outcomes in terms of conservation of natural resources, lessening of environmental problem and can improve concrete's durability and mechanical properties. Lightweight foamed concrete (LFC) is well-known as a low-density concrete with a wide range of applications. It is good in compression but poor under flexural load, as it produces multiple microcracks and cannot withstand the additional stress induced by applied forces without supplementary reinforcing elements. Hence this study was performed to examine the potential use of oil palm spikelets fibre (OPSF) in LFC in order to improve its engineering properties. LFC specimens were strengthened with OPSF fibre at different percentages of 0.15%, 0.30%, 0.45%, and 0.60%. LFC density of 1000 kg/m3 was prepared with a constant cement-to-sand ratio of 1:1.5, and cement-to-water ratio of 0.45. The parameters that had been evaluated were flexural strength, compressive strength and splitting tensile strength. The results revealed that the addition of 0.45% of OPSF fibre gave the best compressive, bending and splitting tensile strengths result. OPSF fibre in LFC aided to evade the promulgation of cracks in the plastic state in the cementitious matrix.

Influence of fine inclusions on the morphology and mechanical performance of lightweight foam concrete

Lightweight foam concrete is a cementitious cellular solid with a series of functional properties. Its non-structural applications potentially permit a high-volume inclusion of particles (e.g., recycled fines). However, the particle inclusion tends to alter the foam morphology and diminish the mechanical performance of foam concrete. To promote the acceptance of particle inclusion while minimizing the performance loss, this work studies the impact of sand inclusions on the mechanical properties of a group of lightweight foam concrete mixtures at 0.4 and 0.6 g/cm3, with various particle sizes and inclusion ratios. The morphology of lightweight foam concrete that is closely related to its mechanical performance is characterized using optical and scanning electron microscope (SEM) imaging. Several tests characterizing the fundamental resonant frequency, elastic modulus, crushing strength, and compressive strength, are also implemented as direct mechanical measurements of the foam concrete samples. Based on the experimental results, a model is derived for predicting the strength of lightweight foam concrete with different particle inclusions. Our study suggests that the degradation of foam structure is the major cause of the loss on mechanical performance, but a high-volume particle inclusion can be achieved with proper implementation.