scholarly journals Water Absorption Properties of Geopolymer Foam after Being Impregnated with Hydrophobic Agents

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4162
Author(s):  
Hiep Le Chi ◽  
Pavlína Hájková ◽  
Su Le Van ◽  
Petr Louda ◽  
Lukáš Voleský
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Positive Impact ◽  
High Sensitivity ◽  
Acoustic Properties ◽  
Total Water ◽  
Absorption Properties ◽  
Major Barrier ◽  
Water Absorption Coefficient ◽  
Hydrophobic Agent

Geopolymer foam is classified as a lightweight material with high porous in its matrix which has great offer for applications requiring fire-resistant, thermal, and acoustic properties. However, the high sensitivity to humid environments can be a major barrier of geopolymer foam that limits the variety of applications of this material. Based on this drawback, two types of hydrophobic agent (Lukosil M130 and Lukofob ELX) were used as an impregnator to treat the surface of geopolymer foam samples. This paper presented the results of water absorption properties of the untreated and treated geopolymer foam composites. The obtained properties were flexural strength, compressive strength, density, total water absorption, the rate of water absorption, and water absorption coefficient. The results showed that the samples after being impregnated with hydrophobic agents improved significantly their waterproof property especially using Lukosil M130. Moreover, the samples treated with Lukosil M130 had positive impact on their mechanical strength.

scholarly journals Exposing Sustainable Mortars with Nanosilica, Zinc Stearate, and Ethyl Silicate Coating to Sulfuric Acid Attack

2018 ◽  
Vol 10 (10) ◽  
pp. 3769 ◽  
Author(s):  
Victoria García-Vera ◽  
Antonio Tenza-Abril ◽  
Marcos Lanzón ◽  
José Saval
Keyword(s):  
Compressive Strength ◽  
Sulfuric Acid ◽  
Mass Loss ◽  
Water Absorption ◽  
Zinc Stearate ◽  
Acid Exposure ◽  
Ethyl Silicate ◽  
Acid Attack ◽  
Water Absorption Coefficient ◽  
Silicate Coating

Obtaining durable materials that lengthen the service life of constructions and thereby contribute to sustainability requires research into products that improve the durability of cementitious materials under aggressive conditions. This paper studies the effects of sulfuric acid exposure on four mortar types (control mortar, mortar with nanosilica, mortar with zinc stearate, and mortar with an ethyl silicate coating), and evaluates which of them have better performance against the acid attack. After 28 days of curing, the samples were exposed to a sulfuric acid attack by immersing them in a 3% w/w of H2SO4 solution. Physical changes (mass loss, ultrasonic pulse velocity, open porosity, and water absorption), and mechanical changes (compressive strength) were determined after the sulfuric acid exposure. A scanning electron microscope (SEM) was used to characterize the morphology of the surface mortars after the exposure. The control mortar had the highest compressive strength after the acid attack, although of the four types, the zinc stearate mortar showed the lowest percentage of strength loss. The zinc stearate mortar had the lowest mass loss after the acid exposure; moreover, it had the lowest capillary water absorption coefficient (demonstrating its hydrophobic effect) both in a non-aggressive environment and acid attack.

scholarly journals Evaluation of the Performance of Bio-Based Rigid Polyurethane Foam with High Amounts of Sunflower Press Cake Particles

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5475
Author(s):  
Agnė Kairytė ◽  
Sylwia Członka ◽  
Renata Boris ◽  
Sigitas Vėjelis
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Polyurethane Foam ◽  
Mechanical Performance ◽  
Positive Impact ◽  
Press Cake ◽  
Rigid Polyurethane Foam ◽  
Average Cell

In the current study, rigid polyurethane foam (PUR) was modified with 10–30 wt.% sunflower press cake (SFP) filler, and its effect on performance characteristics—i.e., rheology, characteristic foaming times, apparent density, thermal conductivity, compressive strength parallel and perpendicular to the foaming directions, tensile strength, and short-term water absorption by partial immersion—was evaluated. Microstructural and statistical analyses were implemented as well. During the study, it was determined that 10–20 wt.% SFP filler showed the greatest positive impact. For instance, the thermal conductivity value improved by 9% and 17%, respectively, while mechanical performance, i.e., compressive strength, increased by 11% and 28% in the perpendicular direction and by 43% and 67% in the parallel direction. Moreover, tensile strength showed 49% and 61% increments, respectively, at 10 wt.% and 20 wt.% SFP filler. Most importantly, SFP filler-modified PUR foams were characterised by two times lower water absorption values and improved microstructures with a reduced average cell size and increased content in closed cells.

scholarly journals Optimization of Processing Parameters of Red Gypsum-Based Brick Manufacturing using Response Surface Methodology

2019 ◽  
Vol 7 (4) ◽  
Author(s):  
Mohd Amirul Hakim Sidek ◽  
Rosli M. Yunus ◽  
Mohammad Al-Nizar Khan Ahmad Khan ◽  
Muhammad Remanul Islam
Keyword(s):  
Compressive Strength ◽  
Response Surface Methodology ◽  
Water Absorption ◽  
Response Surface ◽  
Processing Parameters ◽  
Cost Prediction ◽  
Absorption Properties ◽  
Optimum Solution ◽  
Average Compressive Strength

The red gypsum (RG) is a waste, industrial by product, can be potentially used for brick manufacturing. In the current study, the manufacturing of bricks using RG, sand and cement was optimized using response surface methodology (RSM). The water/cement (w/c) ratio and sand replacement were varied for an optimum compressive strength and water absorption properties of the cement. From the analysis, the average compressive strength of conventional cement brick (CCB) tested was 10.9 MPa. Based on the optimum solution from the RSM analysis, possible cost prediction was estimated which can provide some valuable information to the manufacturer.  

scholarly journals Effects of Adding Silica Fume and Empty Fruit Bunch to the Mix of Cement Brick

2021 ◽  
Vol 3 (1) ◽  
pp. 19-30
Author(s):  
Jen Ling ◽  
Yong Lim ◽  
Wen Leong ◽  
How Sia
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Silica Fume ◽  
Palm Oil ◽  
Absorption Capacity ◽  
Water Absorption Capacity ◽  
Empty Fruit Bunch ◽  
Absorption Properties ◽  
Proper Disposal ◽  
By Products

Silica fume (SF) and palm oil empty fruit bunch (EFB) are the by-products of the ferroalloy smelting industry and oil palm plantation, which require proper disposal to minimize the environmental impacts. To consume the by-products, the feasibility of utilizing SF and EFB to fabricate bricks was studied. Limited studies were adopting EFB as the natural fibres in bricks and its pro-portion barely exceeded 5%. With the enhancement of SF, EFB content in the mix could be increased. In this study, 336 specimens were produced in the cement-to-sand (c/s) ratios of 1:2.5 and 1:3, where SF replaced 10% to 15% cement in the mix by weight while EFB substituted 20% to 25% sand by volume. The specimens were tested for the compressive strength, density, and water absorption properties. SF was found to strengthen the mix, while EFB reduced the compressive strength and increased the water absorption capacity of the brick. Based on the evaluation results, the mix containing less than 10% SF and 20% EFB content was applicable for non-load-bearing brick.

scholarly journals Absorption Characteristics of Lightweight Concrete Containing Densified Polystyrene

2017 ◽  
Vol 3 (8) ◽  
pp. 594-609 ◽  
Author(s):  
Bengin Herki
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Construction Industry ◽  
Lightweight Concrete ◽  
Expanded Polystyrene ◽  
Partial Replacement ◽  
The Novel ◽  
Total Water ◽  
Capillary Water ◽  
Significant Difference

The environmental impacts of the construction industry can be minimised through using waste and recycled materials to replace natural resources. Results are presented of an experimental study concerning capillary transport of water in concrete incorporating densified expanded polystyrene (EPS) as a novel aggregate. A new environmentally friendly technique of densifying was used to improve the resistance to segregation of EPS beads in concrete. Twelve concrete mixes with three different water/cement ratios of 0.6, 0.8 and 1.0 with varying novel aggregate content ratios of 0, 30, 60 and 100% as partial replacement for natural aggregate by equivalent volume were prepared and tested. Total absorption, absorption by capillary action, and compressive strength was determined for the various concrete mixes at different curing times. The results indicated that there is an increase in total water absorption (WA) and capillary water absorption (CWA) and a decrease in compressive strength with increasing amounts of the novel aggregate in concrete. However, there is no significant difference between the CWA of control and concretes containing lower replacement level.

scholarly journals The use of glass waste cullet in the concrete production as an important factor in the circular economy

2021 ◽  
Vol 900 (1) ◽  
pp. 012013
Author(s):  
J Junak ◽  
N Junakova
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Circular Economy ◽  
Negative Impact ◽  
Glass Cullet ◽  
Total Water ◽  
Glass Waste ◽  
Concrete Production ◽  
Aggregate Fractions ◽  
Real Density

Abstract The paper focuses on the use of glass waste as a substitute for aggregates (0/4, 4/8 and 8/16 mm) in the production of concrete in order to reduce the negative impact of existing waste on the environment. For the study, 5 mixtures were designed with gradual replacement of individual natural aggregate fractions in the concrete mixture by glass cullet. Real density, total water absorption and compressive strength were monitored on cubes with an edge of 100 mm for a period of 14 days to 3 years. The achieved compressive strength of samples with glass as a filler at the level of 50 MPa gives a good precondition for the real use of such concrete in practice. In addition, when combined it with lower real density and total water absorption.

scholarly journals Influence of Crystalline Admixtures on the Short-Term Behaviour of Mortars Exposed to Sulphuric Acid

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 82 ◽  
Author(s):  
Victoria García-Vera ◽  
Antonio Tenza-Abril ◽  
José Saval ◽  
Marcos Lanzón
Keyword(s):  
Compressive Strength ◽  
Absorption Coefficient ◽  
Water Absorption ◽  
Sulphuric Acid ◽  
Cementitious Materials ◽  
Pulse Velocity ◽  
Capillary Water ◽  
Short Term ◽  
Water Absorption Coefficient ◽  
Capillary Water Absorption

Using durable materials is a sustainable solution for extending the lifetime of constructions. The use of crystalline admixtures makes cementitious materials more durable. They plug pores, capillary tracts and microcracks, blocking the entrance of water due to the formation of crystals that prevent the penetration of liquids. The literature has covered the performance of these admixtures on concrete, but studies on mortars are still scarce. The aim of this study is to investigate the effect of an aggressive environment (sulphuric acid solution—3 wt%) on mortars produced with different percentages of a crystalline admixture (1%, 1.5% and 2% by weight of cement content). Physical and mechanical properties were studied after immersing the mortars in a H2SO4 solution for 90 days. It was found that, after a 90-day sulphuric acid exposure, mortars with the crystalline admixture showed greater compressive strength than the control mortar, besides exhibiting lower mass loss. However, the crystalline admixture did not produce any significant effect on the capillary water absorption coefficient. In a nonaggressive environment, and in the short term, the crystalline admixture did not have a significant effect on the compressive strength, the capillary water absorption coefficient or the ultrasonic pulse velocity.

scholarly journals The transport properties of cement mortars subjected to freeze-thaw cycles

2018 ◽  
Vol 49 ◽  
pp. 00128
Author(s):  
Alicja Wieczorek ◽  
Marcin Koniorczyk ◽  
Dalia Bednarska ◽  
Kalina Grabowska
Keyword(s):  
Absorption Coefficient ◽  
Water Absorption ◽  
Transport Properties ◽  
Positive Impact ◽  
Gas Permeability ◽  
Cement Matrix ◽  
Capillary Absorption ◽  
Water Absorption Coefficient ◽  
Freeze Thaw ◽  
Cement Mortars

The parameters characterizing the microstructure of cementbased materials, such as porosity or permeability, determine not only durability, but also risk of degradation of the cement matrix due to an aggressive environment. The report presents results of a research on transport properties of cement mortars subjected to cyclic water freezing. Mortars prepared on the basis of two different cements were the object of the research: Portland cement CEM I 42.5R and Portland blast-furnace slag cement CEM III/A 42.5N LH/HSR/NA, with two water-cement ratio (w/c=0.45 and 0.40). The experimental study was carried out in order to determine the relationship between intrinsic permeability and the water absorption coefficient in relation to the number of freeze-thaw cycles. The evolution of transport coefficients was determined using a capillary absorption test and the modified RILEM-Cembureau method. It was established that the degradation processes induced an increase of transport properties. Moreover, the microcracks had a more significant influence on permeability and lesser influence on the water absorption coefficient. The gas permeability of damaged mortar changed very significantly, an increase with several orders of magnitude could be noticed. Moreover, the positive impact of CEM III on ice-induced degradation was also visible.

scholarly journals Effects of Synthetic Foam on the Properties of Stabilized Lateritic Bricks

2021 ◽  
Vol 11 (1) ◽  
pp. 61-69
Author(s):  
Adebimpe Omorinsola Akerele ◽  
Irewolede Aina Ijaola ◽  
Olatunbosun Hezekiel Omolayo
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Construction Projects ◽  
Production Costs ◽  
Dead Load ◽  
Material Management ◽  
Absorption Properties ◽  
Foaming Agent ◽  
Minimum Requirement ◽  
Weak Soils

AbstractManaging the production costs of construction projects is crucial especially in the aspect of material management. The use of lightweight materials reduces the dead load in structures, thus the reduction in the use of reinforcement and concrete in the foundation. To this end, this study examined the effect of synthetic foam on the properties of stabilized lateritic brick with a view to producing lightweight stabilized laterite brick for use on weak soils with low bearing capacity. Laboratory tests were conducted on the bricks produced to determine the density, compressive strength, and water absorption properties at 7, 14, 21, and 28 days. Preformed foam using synthetic foaming agent was used at 0%, 25%, 50%, 75% and 100% to replace the water in the experiment. One hundred twenty samples of stabilized foamed lateritic bricks were produced at a mixed ratio of 1:4 (cement: laterite) using a 0.6 water/cement ratio. The result showed that the bricks at all percentages of foam content meet up with the minimum requirement of compressive strength of 1.6N/mm2, 2.0N/mm2 and 3.5N/mm2 recommended by the Nigerian Building code, Nigerian Building and Road Research Institute, and the third class brick of the BS 3921:1985 respectively. The water absorption is within the limits of bricks specified in standards as 15%. The highest compressive strength was recorded at 25% foam inclusion (4.839N/mm2) on 28th day hence concluding that foaming agent stabilizes the characteristics strength of laterite bricks and also reduces its density.

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