Compressive Strength Behavior Research Articles

The surface treatment of PVA fibres to enhance fibre distribution and mechanical properties of foam concrete

Fibres are often used to improve the mechanical properties of foam concrete. However, the poor dispersion of PVA fibres in foam concrete significantly restricts their reinforcement efficiency. Limited studies have been conducted on improving the distribution of PVA fibres in a cementitious matrix, particularly in relation to foam concrete. This is noteworthy because pore structure, which can be significantly influenced by the fibres and fibre treatment agents, is a critical parameter that affects the mechanical properties of foam concrete. Therefore, this study employed polar agents (non-ionic surfactants) to treat the fibre surface, aiming to enhance the distribution and reinforcement efficiency of PVA fibres in foam concrete. In view of safety and feasibility, two non-hazardous polar agents, namely PEG-PPG-PEG (designated as PA A) and Polyoxyethylene (20) cetyl ether (designated as PA B), were used to treat the PVA fibres. The impact of fibre treatments on fibre dispersion and pore structure was investigated, and the compressive strength and flexural behaviour of foam concrete were measured before and after the treatments. PA A was found to be unsuitable for fibre treatment due to its poor bonding with the fibre surface. On the other hand, PA B exhibited good bonding with PVA fibres, resulting in enhanced fibre dispersion and pore structure in the foam concrete. Compared to plain foam concrete, the fibres treated with PA B increased the compressive and flexural strength by 47.4 % and 190.3 %, respectively. Moreover, the treated fibres (by PA B) were observed to improve the 0.8 mm toughness of foam concrete by 27.2 %.

Compressive properties of AlSi10Mg lattice structures with novel BCCZZ and FCCZZ configurations fabricated by selective laser melting

PurposeThis paper aims to examine the static compression characteristics of cell topologies in body-centered cubic with vertical struts (BCCZ) and face-centered cubic with vertical struts (FCCZ) along with novel BCCZZ and FCCZZ lattice structures.Design/methodology/approachThe newly developed structures were obtained by adding extra interior vertical struts into the BCCZ and FCCZ configurations. The samples, composed of the AlSi10Mg alloy, were fabricated using the selective laser melting (SLM) additive manufacturing technique. The specific compressive strength and failure behavior of the manufactured lattice structures were investigated, and comparative analysis among them was done.FindingsThe results revealed that the specific strength of BCCZZ and FCCZZ samples with 0.5 mm strut diameter exhibited approximately a 23% and 18% increase, respectively, compared with the BCCZ and FCCZ samples with identical strut diameters. Moreover, finite element analysis was carried out to simulate the compressive response of the lattice structures, which could be used to predict their strength and collapse mode. The findings showed that while the local buckling of lattice cells is the major failure mode, the samples subsequently collapsed along a diagonal shear band.Originality/valueAn original and systematic investigation was conducted to explore the compression properties of newly fabricated lattice structures using SLM. The results revealed that the novel FCCZZ and BCCZZ structures were found to possess significant potential for load-bearing applications.

The role of intrinsic soil properties in the compressive strength and volume change behavior of unstabilized earth mortars

Despite the growing interest in earthen construction, there is critical lack of reliable experimental data on the soil properties which mostly affect the engineering characteristics of the dried building material. Therefore, the main objective of this research was to explore the influence of some of these properties, namely clay fraction content, Specific Surface Area (SSA), Cation Exchange Capacity (CEC), chemical and mineralogical composition and various forms of iron and calcium carbonate on earth mortars. The initial trigger for this research was the extraordinary compressive strength of four earth mortars prepared with different soils. So, these four soils, along with seven others from previous research, were thoroughly examined using soil science techniques to investigate the link between soil properties and compressive strength and linear shrinkage of earth mortars. A relationship between the compressive strength to CEC ratio and dry density was found, highlighting the decisive role of clay activity as expressed by CEC, in earthen materials properties. According to linear regression and dominance analysis, the strongest correlation was exhibited by SSA followed by CEC, demonstrating that compressive strength is largely dependent on these two properties. Less strong correlation was found for clay fraction content, while poorly ordered/amorphous iron oxides were found to correlate with strength and shrinkage, but their contribution requires further research. Regarding the mineralogical properties, it was found that the mortars that achieved the highest strengths contained poorly crystalline smectite clays. Finally, even significant differences in soil chemical composition did not necessarily lead to different mortar properties.

Rheological and mechanical behavior study of eco-friendly cement mortar made with marble powder

The work aim is to investigate the rheological and mechanical behavior of eco-friendly mortar made with marble powder. Marble have used as sand by total substitution of natural sand and as additional materials by partial substitution of cement. Firstly, rheological tests were carried out on the cement pastes in order to studying the effect of cement substitution by marble powder on the rheological behavior. Secondly, our study is devoted to evaluate the mechanical performances (flexural strength, compressive strength, mechanical behavior and ultrasonic pulse velocity) of a fluid mortar such as the case of the self-compacting mortars elaborated with the marble powder as addition materials and as a sand. The mechanical test results show that a significantly improved of compressive strength and mechanical behavior of an ecological cement mortar made with marble waste as a natural sand. However, marble-based mortars with 100% of marble sand have given a mechanical strength similar to that obtained by control cement mortar (100% natural sand). It was also noted that it can be obtained an ecological cement mortar made with 30% of marble powder as an addition supplementary materials. This leads to a reduction in cement consumption cad a reduction in CO2 gas emissions caused by cement production.

Investigations into magnesium oxide carbon sequestration foamed concrete: Mechanical performance, microstructure and environmental benefits

Investigations into magnesium oxide carbon sequestration foamed concrete: Mechanical performance, microstructure and environmental benefits

Effect of Glass Powder on the Compressive Strength and Drying Shrinkage Behavior of OPC‐ and LC3‐50‐Based Cementitious Composites of Various Strengths

This study assesses the compressive strength and drying shrinkage behavior of cement and LC3‐50‐based cementitious composites containing glass powder. A total of four, i.e., 20, 35, 50, and 60 MPa, strengths of cementitious composites were targeted by varying the mix composition and water‐to‐cement ratios. In all four composite mix types, locally available glass powder was used as 0, 5, 10, and 15% added as a partial replacement of cement and LC3‐50. The novelty of this research is the addition of waste glass powder as an alternative to silica fume, especially in a high‐strength composite (including 50 and 60 MPa). The aim was to investigate the efficiency of waste glass powder in providing eco‐friendly composites. The compressive strength was determined following ASTM C 109 standard and the drying shrinkage test followed ASTM C 157 standard. The results of compressive strength in the enhancement using up to 10% waste glass powder are beneficial in enhancing strength and reducing drying shrinkage. Furthermore, the use of LC3‐50 initially reduced compressive strength up to 14 days while increased at 28 days compared to OPC. Contrariwise, the initial drying shrinkage was higher in LC3‐50 specimens and lower at later ages compared to OPC. A detailed investigation of existing shrinkage models for mortar/composite is assessed, and limitations are also discussed.

Optimization of non-bearing splice connection in GFRP short columns by manual testing and finite element analysis

Connection designs are established to ensure the stability of joined cut sections, the joints so designed should be based on the optimal performance as per the requirements. The connection joints so established should not be based on just strength but reliability and durability as well. This study focuses on tackling one of the major issues faced when using Glass Fibre Reinforced Polymers (GFRPs) as construction materials, which is based on the abrupt failure of the material under critical or maximum loading. Connection designs are established in GFRP short column H-sections based on Bolted Splicing connections by Eurocode 3 for steel splicing connections. A total of seven Connection designs are established using bearing and non-bearing splicing connections. A total of five models for each connection is established for manual testing and Finite Element Analysis (FEA) is used to simulate and analyze these connection designs. Parameters such as ultimate load, displacement at ultimate load, stiffness, compressive strength, failure mode, load versus displacement behavior graph, and percentage compressive strength compared to the un-cut section are provided in this study. The strongest specimen in this study displaced 128% and 127.7% compressive strength compared to an un-cut GFRP H-section when tested using manual testing and FEA accordingly.

A comprehensive assessment of green concrete incorporated with municipal solid waste incineration bottom: Experiments and life cycle assessment (LCA)

A comprehensive assessment of green concrete incorporated with municipal solid waste incineration bottom: Experiments and life cycle assessment (LCA)

Mechanical behavior of silty-clayey lateritic soil stabilized with recycled municipal solid waste ash

Due to the ever growing need to incorporate ecofriendly and sustainable materials in construction projects, this research study was carried out with the purpose of exploring the feasibility of utilizing recycled municipal solid waste ash (RMSWA) as a sustainable material for stabilizing clayey lateritic soils (LS).The research was aimed at investigating the effect of incorporating varying amounts of RMSWA on the engineering properties of weak soils. Laterite specimens were incorporated with the varying ash contents at intervals of 3%, 6%, 9%, 12% and 15% as replacement levels, and tested for Atterberg limits, compaction and unconfined compressive strength (UCS) behavior. The scanning electron microscopic (SEM) test was conducted to determine the morphology changes in the soil when blended with RMSWA contents at curing ages of 1, 7 and 14 days. Based on the results of UCS test, stress - strain behavior, load - deformation relationships curves were also established and analyzed. Results from the Atterberg limit test revealed that the plastic index, plastic limit, liquid limit ranged between 1.6-11.9%, 20.6-24.5% and 26.1-35.0%. The maximum dry density of the samples increased with the ash inclusion, with the maximum dry density value of 2020Kg/m3 achieved at 6% ash inclusion, thus making it suitable in laterite stabilization.

Comparative analysis of self-cure and dual cure-dental composites on their physico-mechanical behaviour.

Clinical practitioners may have become familiar with the rapid transformation of dental composites. However, they may not scientifically understand the factors influencing the mechanical and physical properties. Scientific knowledge of filler-resin interaction can significantly improve clinical understanding of resin composites. Several independent studies have examined the mechanical and physico-mechanical properties of dental resin composites; however, no comprehensive study has examined the influence of fillers and resin materials on the physico-mechanical properties of both self-cure and dual-cure composites. This study performed investigations on the physico-mechanical behaviour of four commercially available dual-cure dental composites (Bioactive, Fill Up!, Surefil One, Cention N) and two commercially available self-cure dental composites (Stela Capsule and Stela Automix). Test specimens for flexural and compressive strength, microhardness, fracture toughness, and hydrolytic behaviour were prepared and tested as per respective standards. The data sets were statistically analysed using one-way ANOVA and Tukey's post-hoc comparison. There was a substantial variation in flexural strength and modulus values in this study, ranging from 32.0 to 113.4 MPa and 2.36 to 12.07 GPa, respectively. Similarly, there were significant differences in compressive strength between the materials in this study, ranging from 119.3 to 223.5 MPa. The highest fracture toughness value was found to be 1.41 MPa.m0.5, while the lowest value was 0.43 MPa.m0.5. Variations in surface microhardness were significant (24.11-68.0 N/mm2), which correlated with the filler content. Water sorption and solubility demonstrated high variations among materials, with Surefil One exceeding ISO 4049 thresholds significantly. A linear correlation can be established between surface microhardness (HV) and flexural and compressive moduli, as well as filler content (wt.%). However, both flexural and compressive strengths are impacted by the resin's constituent monomers and the resin-filler matrix's cross-linking capability. Additionally, factors such as filler size, shape, and the cross-linking ability of the resin-filler matrix play a crucial role in fracture toughness and the propagation of cracks within the restoration. Also, resin monomers and filler particle size affect the hydrolytic degradation characteristics of composites, which can also affect their mechanical properties. © 2023 Australian Dental Association.

Mechanical Performance of Alkali-activated Stabilized Sandy Soil Reinforced with Glass Wool Residue Microfibers

Mechanical Performance of Alkali-activated Stabilized Sandy Soil Reinforced with Glass Wool Residue Microfibers

Effect of steel fibres and expansive agents on compressive behaviour of circular CFST columns

Effect of steel fibres and expansive agents on compressive behaviour of circular CFST columns

Experimental and FEA Analysis of Bonded Connection in Glass Fiber-reinforced Polymer Short Column

Glass Fibre Reinforced Polymer (GFRP) is a synthetically manufactured material that is derived by compressing multiple layers of glass fiber in a resin matrix. GFRPs can be used as compressive members and hold good compressive strength. These materials display a brittle mode of failure at maximum loading and this aspect is the major disadvantage of these materials. This study intends to tackle this disadvantage by designing and analyzing a connection method called non-bearing spliced connection by Eurocode 3 based on BS EN 1990 and BS EN 1991 guidelines. The connections are established using only bonding as the type of connection. There are two types of bonds established in this study based on the thickness of the epoxy used to establish the bonded connection. A 2 mm thick bond and a 5 mm thick bond are used to create 5 samples of each bond thickness samples. A detailed study of their behavior is established in this study by testing them manually and by using Finite Element Analysis (FEA). The required properties such as failure load, maximum displacement, stiffness, compressive strength, failure modes, and load versus displacement graph behavior are compared and explained in detail in this study.

Continuous surface cap model for ultra-high-performance concrete under static and low strain rate loadings: Calibration, experiment, and simulation

Continuous surface cap model for ultra-high-performance concrete under static and low strain rate loadings: Calibration, experiment, and simulation

Significant reduction in friction and wear of an ultrafine-grained single-phase FeCoNi alloy through the formation of nanolaminated structure

Significant reduction in friction and wear of an ultrafine-grained single-phase FeCoNi alloy through the formation of nanolaminated structure

Effect of loading rate on mechanical properties of autoclaved aerated concrete having steel wool fibres, construction waste and alkaline solution by employing accelerated curing

This paper introduces a new method for developing Autoclaved Aerated Concrete (AAC) blocks, investigating the impact of different loading rates on compressive strength and failure behaviour. Alkaline solution and accelerated curing tank curing were explored as alternatives to conventional methods using aluminium powder and autoclave curing with fly ash. Construction and demolition waste was used as a substitute for fly ash, and chopped steel wool fibres were added to enhance block strength. The blocks were tested under various loading rates, and stress–strain graphs were generated to calculate Young’s modulus of elasticity values. ANSYS software was used for simulation and comparison, validating the accuracy of analytical models. The study shows a correlation between experimental and simulated values, confirming the successful incorporation of CDW and CSWF in AAC block development. Increasing the loading rate during testing leads to lower measured Young’s modulus, indicating strain rate dependency. However, including CSWF enhances Young’s modulus by redistributing stress and restraining crack propagation. The research contributes to understanding AAC's mechanical properties and performance, supporting its potential as a sustainable alternative for masonry materials in structural applications.

Effect of Coarse Aggregate Size on the Performance of PE/HPP Hybrid Fiber Concrete

Three kinds of continuously graded coarse aggregates with maximum particle sizes of 10mm, 16mm and 20mm were selected from pebble and gravel respectively, then, Slump test, compressive strength test and bending toughness test were carried out to study the influence of maximum particle size of coarse aggregate on the workability, compressive strength, wear resistance and bending behaviour of PE/HPP hybrid fiber concrete. The results show that with the increase of the maximum particle size of coarse aggregate, the work performance, compressive strength and bending toughness of hybrid fiber concrete are improved.

FRP spiral strip-confined concrete columns: Stress-strain behavior and size effect

FRP spiral strip-confined concrete columns: Stress-strain behavior and size effect

Influence of carbon dioxide on shrinkage behavior and compressive strength of AAC in accelerated tests

Abstract BackgroundThe German application standard DIN 20000‐404:2018‐04 for the use of AAC according to DIN EN 771‐4:2015‐11 describes a method to determine the long‐term resistance due to carbonation. Thus, the total value of the drying shrinkage as specified in DIN EN 680:2006‐03 must not exceed 0.40 mm/m. This threshold was evaluated using empirical methods.ObjectiveIn order to verify the above threshold, additional studies were carried out in this paper on AAC blocks from different manufacturers.ExperimentalDeviating from the standard climate according to DIN EN 680:2006‐03, a parametric study was carried out under laboratory conditions. All AAC specimens were stored at a relative humidity of 80% and a carbon dioxide concentration of 0.5% by volume. In addition to the shrinkage behavior, the compressive strength behavior of the AAC specimens with increasing carbonation progress was investigated.ResultsThe degree of carbonation of the individual AAC types progresses at different rates. AAC that carbonates faster shows a greater change in length (up to about 5.2 mm/m) and a significant loss in compressive strength (up to about 50%). In some cases, the compressive strength initially increases before decreasing again. AAC containing fly ash only shows an increase in compressive strength with progressive carbonation.ConclusionsThe determination of the total value of drying shrinkage according to DIN EN 680:2006‐03 appears to be the most suitable method so far to identify AAC blocks with an increased risk towards carbonation with a manageable effort. The accompanying compressive strength tests indicate that the specified limit value of 0.40 mm/m according to DIN 20000‐404:2018‐04 is also appropriate.

Effect of mix design parameters on the behavior of compression cast concrete

Compression casting is a novel method for producing high-performance concrete. However, the optimal mix design parameters for normal concrete (NC) may not be suitable for compression cast concrete (CCC) due to the high compression pressure involved during casting. This study addresses the lack of research on CCC mix design and examines the influence of different parameters, including aggregate gradations, maximum particle size, sand ratios, and water-to-cement (w/c) ratios, on the performance of NC and CCC. Fourteen groups of concrete samples were prepared with varying aggregate grading, particle sizes, sand content, and w/c ratios. The density, compressive strength, elastic modulus, peak strain, and stress-strain behavior were analyzed. CCC specimens exhibited superior stress-strain relationships compared to NC specimens. CCC can be produced with different aggregate gradings and particle sizes. Notably, CCC specimens with a maximum aggregate size of 25 mm and no particles between sizes 5 mm and 9.5 mm (grading - 4) demonstrated the highest compressive strength and elastic modulus. CCC specimens with a sand ratio of 38% outperformed those with ratios of 28% and 48%. Increasing the w/c ratio showed similar stress-strain behavior for both NC and CCC specimens. This study proposes relationships between the properties of NC and CCC based on the findings. The results provide valuable theoretical and experimental insights for engineering applications involving CCC, considering different aggregate grading, particle size, sand ratio, and w/c ratio combinations.