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 sorptivity, initial surface absorption, and 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. The result shows that eggshell powder improves sorptivity, initial surface absorption, and dimensional stability of lightweight foamed concrete and the optimal replacement level is 5%. The result also shows that calcium stearate significantly improves these properties, regardless that incorporation of eggshell powder in the mixture containing calcium stearate might slightly deteriorate these properties. Besides, based on the results, improved sorptivity and initial surface absorption result in increased magnitude of shrinkage as the specimen has lower ability to absorb water for expansion throughout the testing period

Effect of Ceramic Dust as Partial Replacement of Cement on Lightweight Foamed Concrete

Disposal of waste into the landfill causes a severe impact on the environment. One of the waste products is ceramic waste. Ceramic waste has some excellent properties in its durability, hardness, and highly resistant to biological, chemical, and physical degradation forces. These excellent properties of the ceramic waste may make it suitable to be used in concrete. This study investigates the effect on the compressive strength of lightweight foamed concrete with different percentage of ceramic dust replacement level towards the cement and three different levels of water-cement ratio. 0%, 5%, 15%, and 25% of replacement level with 0.52, 0.56, and 0.60 water-cement ratios respectively for each replacement level was used as the parameter to investigate the fresh properties, and strength performance of lightweight foamed concrete. The stability and consistency of every mix are studied as well. From this study, it was observed that the incorporation of ceramic waste dust partially replaced the cement did not affect on the fresh properties of the foamed concrete. However, the compressive strength of foamed concrete affected by ceramic waste dust partially replaced the cement

Flexural behaviour of reinforced slab panel system with embedded cold-formed steel frames as reinforcement

This paper presents the experimental investigation on flexural characteristic of slab panels with embedded cold-formed steel frame as reinforcement. Perforated cold-formed steel channel sections are formed into steel frames as replacement to the conventional reinforcement bars inside precast concrete slab panels. A series of six experimental specimens for precast slab panels were tested. The specimens with 3 configurations namely control sample (CS) with conventional reinforcement bars, single horizontal C-channel section (SH) and double horizontal C-channel sections (DH) formed into rectangular hollow section. Results show that the tested slab specimens failed at the flexural crack at mid-span, under loading point and shear at the support. Tearing of shear connector in the cold-formed steel section was found to be the main factor for the structural failure. SH specimens achieved the highest ultimate load capacity, with average value of 138.5 kN, followed by DH specimens, 116.5 kN, and the control samples, 59.0 kN. The results showed that the proposed reinforced slab panel with embedded cold-formed steel frame was more effective compared to conventional reinforced sla

Acoustic properties of lightweight foamed concrete with eggshell waste as partial cement replacement material

Nowadays, almost every industry needs to undergo green and sustainable industrial revolution due to pollutions like waste dumping and noise that deteriorating the environment. Therefore, feasibility study on application of eggshell waste as partial cement replacement in lightweight foamed concrete was conducted by aiming to solve environmental and acoustical issues, i.e. reduce eggshell waste and improve acoustic properties. In this study, compressive strength and acoustic properties of 1300 kg m-3 lightweight foamed concrete with and without 5% eggshell powder as partial cement replacement material were tested. Optimal water to cement ratio of 0.6 was obtained for acoustic properties test by comparing compressive strength result. The result shows that application eggshell powder has generally reduced 7 days compressive strength but improved 28 days compressive strength, and either improve or maintain acoustics properties, in which lightweight foamed concrete that containing eggshell powder has improved noise reduction coefficient at testing ages of 7, 28, and 90 days and improved sound transmission class at testing age of 56 and 90 days. Based on these results, 5% of eggshell powder is feasible to be incorporated into lightweight foamed concrete as partial cement replacement material for sound insulation and strength development purposes

Knowledge for games, games for knowledge: designing a digital roll-and-move board game for a law of torts class

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Effect of filler on strength development of epoxy grout

Epoxy grout is used for most structural repair works due to its high strength, adhesive and availability. This study uses epoxy resin and its hardener as binder, graded sand and ground granulated blast furnace slag (GGBFS) as filler to produce the epoxy grout. The objective is to produce a sufficient mix proportion for epoxy grout that has good workability and high strength properties, which can be used as structural repair material. The method used to obtain the mix proportion was by trial mix as determined by flowability and strength of the grout. Several batches of epoxy grouts with different epoxy: hardener: filler ratios were designed and tested for its flowability and compressive strength properties. Finally, the mix proportion with fresh properties, namely viscosity or flowability that fulfills the requirements of ASTM C 881 and has optimum strength development was selected. The optimum compressive strength obtained for epoxy grouts with 5:1:11 epoxy:hardener:filler ratio was above 70 MPa for air cured specimen, which can be considered as high strength repair material. The results for slag based epoxy grout showed that the replacement of slag up to 50% as filler to epoxy mix with proper mix proportion is suitable to be used in concrete structural repair

Engineering properties of high volume slag cement grout in tropical climate

Concrete repair is a complex process. It must successfully integrate new material with the old one to form a lasting composite that can withstand harsh environment. Cement based grout is used for most general repair works due to its low cost and availability. This research, however, used ordinary Portland cement and ground granulated blast furnace slag (GGBFS) as binders to produce a slag cement based grout. The research objective is to produce a sufficient mix proportion for slag cement based grout that has good engineering properties and can be used as concrete repair material in tropical climates. Flow cone test was used to determine the mix proportions of cement grout. Several batches of 50% slag replacement cement mixes were designed and tested for its flowability and compressive strength properties. Finally, the mix proportion with fresh properties, namely workability, bleeding, and setting time that fulfill the requirements of ASTM C 937 and has optimum strength development was selected. The optimum compressive strength obtained for 50% slag replacement cement grout was above 30 MPa and its flexural strength was above 9 MPa under water curing condition. Result of drying shrinkage test strengthened the finding that the replacement of 50% slag as binder to cement mix with proper mix proportion is suitable to be used in normal grade concrete repairs under tropical climate

Compressive Strength and Dimensional Stability of Palm Oil Empty Fruit Bunch Fibre Reinforced Foamed Concrete

Rapid drying shrinkage is an important factor in causing cracks of concrete. This research was aimed at studying the effects of Palm Oil Empty Fruited Bunch (POEFB) fibre on the drying shrinkage behaviour and compressive strength of foamed concrete (FC) under two different curing conditions. The adopted curing conditions were air curing and tropical natural weather curing. Two volume fractions of POEFB fibre were used, which were 0.25% and 0.50% based on dry mix weight with 1-2 cm in length. The dimensional stability of the control specimen and POEFB fibre reinforced FCs was obtained by cumulating the measured linear shrinkage or expansion due to different curing conditions. The results from the two different specimens were compared. The results showed that specimens reinforced with POEFB fibre and cured under tropical natural weather condition attained lesser variations of dimensional stability and higher 90-day strength performance index than the reference mix without POEFB fibre. This improvement was attributed to the ability of POEFB fibre to bridge the cement matrix, and irregular wetting process under tropical natural weather curing condition had enabled more production of Calcium Silicate Hydrate gels that gradually blocked the penetration of water into the specimens and increased the compressive strength. It is observed that 11.43% and 4.46% of improvement in 90-day strength performance index were obtained in natural weather cured 0.5% of POEFB fibre reinforced specimen, with corresponded to the reference mix and 0.25% of POEFB fibre reinforced specimens, respectively