scholarly journals Efficacy of expanded polystyrene as fine aggregate in cement mortars modified with latex paint as an alternative to polymer admixture

2020 ◽  
Vol 29 (1) ◽  
pp. 163-168
Author(s):  
Banjo A. Akinyemi ◽  
John Ojediran ◽  
Olamide Olawale ◽  
Stephen Ayanwola

AbstractIn this present study, the effectiveness of expanded polystyrene (EPS) waste used as 20, 40 and 60% fine sand replacement in development of lightweight cement composite was evaluated. The cement mortar was strengthened by 10% low cost latex paint emulsion as an alternative to the more expensive polymer admixtures. Six different mix designs were produced and tested for compressive and split tensile strength according to BS EN standards. Scanning electron microscope (SEM) analysis was also conducted to analysis the micrograph of the samples. It was observed that as the EPS content, latex paint polymer admixture and curing days were increased, marginal increment in compressive strength was obtained. However, EPS fines were most effective in improving the split strength while latex paint admixture had comparatively less part to play in the strength development. The micrograph images showed that the EPS fines were uniformly distributed within the microstructure and the latex paint developed polymer films. These mechanisms coupled with the cement hydrate products were responsible for the enhanced strength observed in the samples.

2019 ◽  
Vol 276 ◽  
pp. 01025
Author(s):  
Tri Mulyono ◽  
Anisah

The benefit of pervious concrete lies in its ability to transport a large volume of water through its pores to the underlying strata, and it often serves as a pavement for vehicles and pedestrians. This research aimed to determine the properties of pervious concrete based on trials in the laboratory. The method used in this research was a laboratory experiment in accordance with the appropriate standards. The local material used in the mixture was a material composition with Portland Cement Composite with a water-cement (W/C) ratio 0.27 to 0.34, with aggregates of various types and sizes and fly ash and superplasticizer as the added ingredients. The mixture for the trial used 4.25 for the aggregatecement ratio (A/C) with a proportion of 6% for the fine aggregate (sand), 15% flay ash and a low dosage of superplastizer. The test results showed a slight difference in compressive strength and split tensile strength alongside variations in the W/C, including the use of different aggregate types and sizes. The permeability when using natural aggregate was more porous compared to the crushed stone. The effect of the aggregate size from small to large will result in decreased density (unit weight) and increased void in the mixture. Good agreement was reached in the 0.30 wcr mixture with an aggregate size that passed through a 12.5 mm sieve, that was retained at 9.5 mm and that provided suitable compressive strength.


2021 ◽  
Vol 879 ◽  
pp. 275-283
Author(s):  
Koay Mei Hyie ◽  
Salina Budin ◽  
Normariah Che Maideen ◽  
Yudi Rahmawan

Fasteners are commonly used in construction industry for parts joining purpose. There are many types of construction fasteners such as stud, bolt, anchor, nut, screw, and washer. The major problem of the fastener made by carbon steel is the poor resistance to corrosion. Electroplating is a simple yet low-cost tool to give a strong corrosion protection coating layer on the carbon steel. This study was performed to investigate the effect of current and deposition time on the iron triad (cobalt-nickel-iron) electroplating on the fastener washer. The experiment was conducted at 50 °C, pH 1-3 and at different electroplating time (30 minutes to 90 minutes) and current (0.2 A to 0.5 A). Burnt-out surface coating was observed on the fastener washer when the current was more than 0.4 A. A field test was carried out for 60 days to observe the corrosion behavior and performance of the products. Scanning electron microscope (SEM) analysis showed that a thin protection layer with 5.64 µm was formed at 60 minutes of electroplating time and 0.4 A of current. The surface roughness of the fastener washer was increased by increasing the electroplating time and current. The hardness was also improved with higher current and electroplating time if compared to the original fastener washer. The result of this study confirmed that a strong adhesive corrosion resistant layer to the fastener washer was using the current of 0.4 A (77 mA/cm2) and the electroplating time of 60 minutes.


2020 ◽  
Vol 15 (4) ◽  
Author(s):  
Mahesh Mallampati ◽  
Sreekanth Mandalapu ◽  
Govidarajulu C

The composite materials are replacing the traditional materials because oftheir superior properties such as high tensile strength, low thermal expansion, high strength to weight ratio, low cost, lightweight, high specific modulus, renewability and biodegradability which are the most basic & common attractive features of composites that make them useful for industrial applications. The developments of new materials are on the anvil and are growing day by day. The efforts to produce economically attractive composite components have resulted in several innovative manufacturing techniques currently being used in the composites industry. Generally, composites consist of mainly two phases i.e., matrix and fiber. In this study, woven roving mats (E-glass fiber orientation (-45°/45°,0°/90°, - 45°/45°),UD450GSM)were cut in measured dimensions and a mixture of Epoxy Resin (EPOFINE-556, Density-1.15gm/cm3), Hardener (FINE HARDTM 951, Density- 0.94 gm/cm3) and Acetone [(CH3)2CO, M= 38.08 g/mol] was used to manufacture the glass fiber reinforced epoxy composite by hand lay-up method. Mechanical properties such as tensile strength, SEM analysis, hardness test, density tests are evaluated.


Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6684
Author(s):  
Miltiadis Zamparas ◽  
Grigorios L. Kyriakopoulos ◽  
Marios Drosos ◽  
Vasilis C. Kapsalis

The research objective of the study is the estimation of a novel low-cost composite material f-MB (Fe-modified bentonite) as a P and N adsorbent from wastewaters. Τhe present study aimed at examining the phosphate and ammonium removal efficiency from different types of wastewater using f-MB, by conducting bench-scale batch experiments to investigate its equilibrium characteristics and kinetics. The SEM analysis revealed that the platelets of bentonite in f-MB do not form normal bentonite sheets, but they have been restructured in a more compact formation with a great porosity. Regarding the sorption efficiencies (Qm), the maximum phosphate sorption efficiencies (Qm) calculated using the Langmuir model were 24.54, 25.09, 26.13, 24.28, and 23.21 mg/g, respectively, for a pH range of 5 to 9. In addition, the maximum NH4+-N adsorption capacities (Qm) calculated from the Langmuir model were 131.8, 145.7, 168.5, 156.7, and 159.6 mg/g, respectively, for a pH range from 5 to 9. Another important finding of this study is that f-MB can recover P from treated wastewater impacting on resource recovery and circular economy (CE). The modified clay f-MB performed the phosphate and ammonium recovery rates of 80% and 78.5%, respectively. Finally, f-MB can slowly release the largest proportion of phosphate and ammonium ions for a long time, thus extending the application of the f-MB material as a slow-release fertilizer and soil improver.


2020 ◽  
Vol 11 (4) ◽  
pp. 11891-11904

In the present study, batch mode adsorption was carried out to investigate the adsorption capacity of dried bael flowers (Aegle marmelos) for the adsorptive removal of Cu(II) ions from aqueous solutions by varying agitation time, initial metal concentration, the dose of adsorbent, temperature, and initial pH of the Cu(II) ion solution. The percentage removal of 98.7% was observed at 50 ppm initial metal ion concentration, 0.5 g/100.00 cm3 adsorbent dosage, within the contact time of 120 minutes at 30 ºC in the pH range of 4 – 7. The sorption processes of Cu(II) ions was best described by pseudo-second-order kinetics. Langmuir isotherm had a good fit with the experimental data with 0.97 of correlation coefficient (R2), and the maximum adsorption capacity obtained was 23.14 mg g-1 at 30 ºC. The results obtained from sorption thermodynamic studies suggested that the adsorption process is exothermic and spontaneous. SEM analysis showed tubular voids on the adsorbent. FTIR studies indicated the presence of functional groups like hydroxyl, –C-O, –C=O, and amide groups in the adsorbent, which can probably involve in metal ion adsorption. Therefore, dried bael flowers can be considered an effective low-cost adsorbent for treating Cu(II) ions.


Author(s):  
Adriane Pczieczek ◽  
Adilson Schackow ◽  
Carmeane Effting ◽  
Itamar Ribeiro Gomes ◽  
Talita Flores Dias

This study aims to evaluate the application of discarded tire rubber waste and Expanded Polystyrene (EPS) in mortar. For mortars fine aggregate was replaced by 10%, 20% and 30% of rubber and, 7.5% and 15% of EPS. We have verified the consistency, density, amount of air and water retentitivity in fresh state. The compressive strength, water absorption, voids ratio and specific gravity have been also tested in hardened state. The application of rubber powder contributed to the increase in entrained air content and in reducing specific gravity, as well as reducing compressive strength at 28 days. The addition of EPS also contributed to the increase of workability, water absorption and voids ratio, and decreased density and compressive strength when compared to the reference mortar. The use of rubber waste and EPS in mortar made the material more lightweight and workable. The mortars mixtures containing 10% rubber and 7.5% EPS showed better results.


Author(s):  
S. E. Ubi

The use of polystyrene beads in concrete applications has been limited due to its perceived low strength properties. Tensile strength test is an important test that determines the vulnerability of concrete to tensile cracking due to the weight of the structural load. Water, sand, coarse aggregates, expanded polystyrene beads, and ordinary Portland cement are the materials used for this study. All the materials were batched according to their weight, except for polystyrene and coarse aggregates which were batched in volume after mixing them together. The polystyrene partial replacement level was considered at 12% of the coarse aggregate volume. The model equation adopted for this study was based on Scheffe’s {4, 2} simplex lattice design for both Pseudo component and component proportional models. The actual model was developed from the 28th day test result. The Mathlab and Minitab 16 software were used in this study to generate the actual mix ratios. The results obtained showed that both Pseudo component and component proportional models both produced an average split tensile strength of about 5.10N/mm2. This implied that the results of this study produced a split tensile strength result that varied between 18% - 19% of its compressive strength result. This showed that the materials and the mix ratios optimized in this study are suitable as building blocks for residential low rising buildings and as partition slaps for high rising buildings. The lightweight property makes it highly suitable for large scale application in high rising structures as internal partition slaps only.


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