Compressive Strength Values Research Articles

Formulation of a Mixture of Nutmeg Shell Waste with Coarse Aggregate for Optimal Compressive Strength Values in Lightweight Concrete

Nutmeg shell waste (CP) has light and hard characteristics which can be used as a replacement material for coarse aggregate for lightweight concrete. The aim of the research is to determine the influence of aggregate characteristics after being mixed with nutmeg shells as a constituent material for concrete and determine the compressive strength value of the concrete. The method used is a laboratory experimental method with CP waste percentages of 2.5%, 5% and 7.5% of the sand volume. The results of the research show the effect of using nutmeg shells in the concrete mixture, where the compressive strength value of the concrete increases along with the increase in CP waste used. The compressive strength values of nutmeg shell concrete (CP) at compositions of 2.5%, 5% and 7.5% were obtained at 234.26, 263.56 kg/cm2, kg/cm2 and 280.14, increasing at 28 days.

SHEAR STRENGTH PARAMETERS AND DEFORMABILITY PROPERTIES OF SILICATE-BASED RESIN ADDED SAND-TYPE SOIL SPECIMENS

In this study, the shear strength, uniaxial compressive strength (UCS) values and deformability properties of silicate-based polymer resin added silty sand type soil specimens were examined through a series of experimental studies. Although the UCS and shear strength values increased, minor decreases in the internal friction angle values were measured as the resin ratio increased. It was determined that the main reason of improvement in the strength values due to the increase in resin content is the increase in cohesion values. It was found that the UCS values calculated according to the cohesion and internal friction angle parameters of the Mohr&Coulomb failure criterion (UCSc) were 2.6-3.0 times lower than the values obtained from the direct UCS experiment. According to this finding, it was concluded that the Mohr&Coulomb failure criterion is not properly usable to represent the mechanical behaviors of resin added sands. As another outcome, the ratio between UCS/UCSc slightly decreased with an increase in the resin amount. In other words, it has been determined that the Mohr&Coulomb failure criterion gives a bit more inaccurate results for the specimens with low binder contents. With the increase in the resin content ratio, significant increases were obtained in both elastic modulus and ductility properties of the samples. It has been evaluated that the silicate-based polymer resin binder is advantageous to provide significant increases in the toughness and energy absorption capacity of soils.

Increasing the strength of alkali activated mortars prepared without cement by adding lime and crushed brick

Alkali-activated concretes, which aim to reduce cement, have received the most attention in recent years. By activating cementless geopolymer mortar samples with lime, blast furnace slag [BFS], fly ash [FA], crushed brick, sodium hydroxide, and sodium silicate, the study aims to produce more affordable and environmentally materials. Hydrated lime and crushed brick mortars, which have been utilized in ancient structures for thousands of years, have endured to the present day because of their toughness and appropriate construction techniques. However, the biggest disadvantage of ancient mortars is that their setting time is long due to the lime they contain and therefore their strength properties cannot be developed at an early age. In order to improve these properties of the mortars, 7.5 mole NaOH was used in fixed ratios and Na2SiO3 in variable ratios. On the mortar’s characteristics, the impacts of lime, crushed brick, BFA, and FA were examined. Tests on the generated samples included flow-table, setting-time, density, water absorption, porosity, flexural and compressive strength tests, as well as SEM, XRD, and FTIR studies. The reference ancient mortar sample has the lowest compressive strength value at 1.47 MPa, while the Y4 sample, which has a high BFS content at 22.5 MPa, has the highest compressive strength value. The YS4 sample comprising BFS, NaOH, and Na2SiO3 had the fastest setting time, at 20 minutes. In comparison to the reference samples, the samples’ workability was also enhanced. The reference sample had the highest water absorption value, 26.8%, while the other samples’ values stayed below 2%. In this case, activators contributed to the improvement of the mechanical qualities of traditional lime mortars.

Investigating the Compressive Strength of Clay Brick Masonry: A Case Study of Nangarhar, Afghanistan

In Afghanistan, masonry structures using burnt clay bricks have long been used for public and private buildings. However, still, there is no standard for masonry structural design based on local material properties. This study investigated the compressive strength of clay brick masonry prisms in Nangarhar, Afghanistan, through experimental testing and finite element modeling (FEM). Three brick classes, with compressive strengths between 8 and 14 MPa, were used to construct prism specimens. The research aimed to propose specific values for masonry compressive strength using local materials and examine the effects of brick strength (fb), mortar strength (fj), joint thickness (tj), and slenderness ratio (h/t) on masonry compressive strength (fm). Test results showed fm values of 17.2 MPa for first-class, 10.0 MPa for second-class, and 7.6 MPa for third-class brick masonry, indicating the influence of the brick’s quality. Key findings showed that an increase in fb causes an equal increase in fm, a 5% increase in fj leads to a 1% increase in fm, a 5 mm increase in tj gives an 8% fm increase, and a 5.5% increase in h/t results in a 1% decrease in fm. The research provides valuable information for evaluating the compressive strength of masonry structures based on the quality of local materials, which can be used to revise Chapter 7 of the Afghanistan Building Code, 2012.

Influence of inherent anisotropy on the mechanical properties of normally consolidated clays with a wide range of plasticity indices

Inherent (fabric) anisotropy is one of the most important properties of earthen materials which has a significant influence on their strength and stiffness characteristics. In this study, a comprehensive series of unconfined and constrained compression tests is performed on normally consolidated (NC) clay samples with different plasticity indices to examine the effect of inherent anisotropy on their mechanical characteristics. Accordingly, several cylindrical clay samples with different proportions of kaolinite and bentonite are reconstituted at a wide range of deposition angles and then subjected to both unconfined and constrained compressive loadings. According to the experimental results, for a clay sample with a particular plasticity index, the highest and lowest values of the unconfined compressive strength (UCS), the secant modulus (E50), and the constrained Young's modulus (Eoed) are observed to be associated with the deposition angles of 0o and 90o, respectively. The results also show that at a certain bedding plane angle, the sample containing 30% bentonite (PI = 110%) exhibits the highest UCS, E50, and Eoed values. Several practical empirical correlations are developed to estimate the strength and stiffness properties of NC clays using their plasticity indices and bedding plane directions. Scanning Electron Microscopy (SEM) analysis is also conducted to explore the microstructure of samples containing varying percentages of kaolinite and bentonite.

Bio-cementations: A Review on Enzyme and Microbially Induced Calcite Precipitation Mechanisms and Applications in Geotechnical Engineering

Modern methods to improve soil must deal with sustainable and green building purposes, and precipitated calcite is the most modern bio-cementation method to improve soil sustainably. Enzyme-induced calcite precipitation and microbially-induced calcite precipitation are precipitated calcite's best branches in bio-cemented soil improvement. EICP and MICP contain calcium chloride, urea, water, urease enzyme and other chemical materials (for MICP As nutrients for bacteria) that are mixed together to precipitate calcium carbonate in the soil. The precipitated calcium carbonate was worked as a binder between soil particles, filling the void and improving the soil's properties. By utilizing this technique in the field, several researchers were able to achieve favorable outcomes in the areas of soil improvement and other engineering applications, including concrete repair and other applications, while also taking into consideration the objectives of sustainability. treatment carried out on soils with one or many cycles of the treatment solution. The treatment revealed a significant improvement in the value of unconfined compression strength, compared to untreated soils. During certain experiments, the unconfined compression strength revealed that soils treated with the enzyme approach exhibited higher values compared to soils treated with a mixture containing a certain proportion of regular Portland cement. The encouraging outcomes that were achieved through the utilization of this test in both the laboratory and the field can be utilized in large-scale operations. Till now, this method has been considered under study. In Iraq there are no any research in term of EICP treatment while there are several research about using MICP in soil treatment.

Evaluation of fly ash-based geopolymer concrete incorporating coarse and fine recycled aggregates

Geopolymer Concrete (GC) is emerging as a promising material due to its lower carbon footprint compared to conventional Portland Cement (PC) concrete. One of the ways to further enhance the sustainability of GC is by incorporating Recycled Aggregates (RA). This study focuses on evaluating the performance of GC made with Coarse Recycled Aggregate (CRA) and Fine Recycled Aggregate (FRA). The mechanical property in terms of compressive strength and long-term durability properties, such as the Capillary Suction Test (CST), Initial Surface Absorption Test (ISAT), and acid attack test, were evaluated for all GC mixes. Ultrasonic Pulse Velocity (UPV) test and the electrical resistivity test, have also been done on all GC mixes. The results show that FRA beyond 25%, along with 50% CRA, is having an adverse impact on the long-term durability properties of GC. The GC mix with a combination of 50% CRA and 25% FRA shows at par compressive strength and electrical resistivity values relative to the Natural Aggregates (NA) GC. The findings from this study are expected to provide valuable insights into the optimal use of RA in GC and contribute to the broader goal of developing sustainable construction materials.

Effect of cementitious capillary crystalline waterproof material on the mechanical behavior of concrete

Cementitious capillary crystalline waterproof material (CCCW) is a material that can react with substances inside the concrete, generating crystals that fill the pores and cracks in the concrete. This chemical reaction is expected to improve the mechanical properties of the concrete. This study investigated the effects of CCCW content and water-cement ratio (W/C) on the compressive behavior of cementitious capillary crystalline waterproof concrete (CCCWC). The results indicated that as the CCCW content increased from 0% to 1.5% for W/C of 0.4, the compressive and tensile strength values of concrete slightly decreased. This is because excessive CCCW generates too many crystals within the concrete, leading to internal matrix expansion and crack formations. However, in the cases of W/C of 0.45 and 0.5, the compressive and tensile strength values of the CCCWC increased wit increasing CCCW content from 0% to 0.5%, but declined with 1.5% CCCWC addition. The reaction between CCCW and concrete generates numerous crystals, which densify the concrete matrix and enhance its strength. Moreover, with increasing W/C, the CCCWC's compressive strength and tensile strength decreased due to the increased porosity of the concrete matrix and the reduced availability of the concrete constituents that react with CCCW. Furthermore, the appropriate choice of CCCW content and W/C can significantly enhance the slope and peak stress of the stress-strain curve. Based on this, a compressive constitutive model of CCCWC was established. The findings showed that the optimal CCCW content varied with W/C. For instance, for a W/C of 0.4, the maximun compressive strength of 54.82 MPa was achieved without any CCCW addition. In contrast, the addition of 0.5% CCCW to concrete produced with W/C of 0.45 and 0.5 resulted in the highest compressive strengths of 50.98 MPa and 44.90 MPa, respectively.

Physical and Mechanical Properties of Mortar Mixed with Paper Mill Waste

The industrial and construction sectors are experiencing continuous growth each year. Concrete, which is used as the main material in construction, is composed of cement, aggregate and water. Research on mortar and aggregate is carried out to create concrete according to the required specifications of certain buildings. However, 8% of global carbon dioxide emissions come from the cement manufacturing process which is one of the main materials in mortar. In the industrial sector, the paper industry is one of the top producers of waste, approximately 48 tonnes for every 100 tonnes of pulp produced. The main wastes of this industry include slaker grits, dregs, lime mud and fly ash which only end up in landfill. To address this problem, this research investigates the modification of mortar mix materials by utilising paper mill waste. Specifically, fly ash and grits are used as substitute for cement and fine aggregate, respectively. Results indicate that the density value of concrete decreased with the increase of fly ash mixture, and the compressive strength value of mortar with varying additions of 0%, 10%, 20%, 30%, 40% and 50% fly ash reached 7.42, 6.68, 6.18, 4.97, 3.93 and 2.97 MPa. The decrease in density and compressive strength with increasing fly ash content can be attributed to the lower adhesive power of waste compared to cement owing to its lower lime oxide content. The value of compressive strength samples 1, 2 and 3 belong to the N type, which can be used as load-bearing walls, while samples 4, 5 and 6 fall into the O type, which can be used as non-load-bearing and decorative walls in accordance with SNI 03-6882-2014 standards.

Strength properties of concrete containing palm bunch ash–calcined anthill clay

AbstractThis study evaluated the strength properties of concrete produced with palm bunch ash–calcined anthill clay (PBA-CAC) as pozzolans. Two groups of palm bunch ashes were produced: ashes generated by burning only palm bunches (PBA) and ashes obtained by blending palm bunches and anthill clay at elevated temperatures (PBA-CAC). The PBA and PBA-CAC satisfied the requirements of Class C pozzolans. The concrete constituents were batched by mass, and the cement–fine aggregate–coarse aggregate ratio was 1:2:4. The cement content was partially substituted with PBA and PBA-CAC at 5%, 10%, 15%, 20%, and 25%, with the 0% specimen serving as the control. The concrete cubes were cured for 7, 14, 28, 56, and 90 days, whereas the concrete cylinders and beams were cured for 7, 28, 56, and 90 days. The 28th day strength values of the control specimens exceeded those of the PBA and PBA-CAC concrete specimens. By the 90th day of curing, the strength values of the specimens produced with 5% PBA and 5% PBA-CAC exceeded those of the control specimen. The PBA-CAC specimens generally had higher values of compressive strength, splitting tensile strength, and flexural strength than PBA specimens containing the same amount of pozzolan.

Assessment of Strength Properties of Clayey Sand Soils Admixed with Marble Powder, GGBS and Geotextile Reinforcement

The use of clayey sand is considered as a low-quality subgrade for pavement construction and presents several challenges. Clayey sand typically has poor engineering properties due to its less strength and high compressibility with moisture changes. This research work is mainly focused on the feasibility of clayey sand to make suitable to use as a subgrade soil when admixed with and ground granulated blast furnace slag (GGBS), which is also termed as Furnace Slag and Marble Powder and reinforced with geotextile. The aim is to evaluating the suitability and find optimum quantities of these additives in improving the soil’s engineering parameters. Different tests were conducted on the soil samples such as grain size distribution, Atterberg’s limits, compaction, California Bearing Ratio (CBR) and Unconfined Compressive Strength (UCS) by different amounts of additives. The soaked and unsoaked California Bearing Ratio values of soil reinforced with Geotextile increased to 4.2% and 6.8%, respectively, at 6% of marble powder. A similar trend of increased strength found in case of Furnace Slag admixed with soil reinforced with geotextile and found as 3.6 and 6.8%, respectively. However, it was found that beyond 6%, there is a decline in California Bearing Ratio, indicating that excess Marble Powder and Ground Granulated Blast Furnace Slag negatively impacts soil strength. The use of geotextile reinforcement significantly enhanced Unconfined Compressive Strength values, with the best performance observed at 6% of Furnace Slag and 8% of Marble Powder obtained as 22.6 kPa and 19 kPa, respectively. Based on the results improvements in subgrade soil strength characteristics, the proposed methodology can be adopted for enhancing strength properties of clayey sand subgrades.

An Empirical Investigation of Static Compression Tests on Mortar Composite Materials with Different Proportions of Fly Ash

The engineering of composite mortar materials presents substantial economic advantages and significant potential for advancement in the construction sector, particularly through applications such as plant vases, coral transplant media, seawalls, wall decorations, bricks, paving blocks, and acoustic panels. The use of fly ash, an industrial byproduct, can facilitate the production of high-quality materials in alignment with the government’s circular economy initiatives. This study employs a mortar mixture with a 1:1 ratio combined with varying compositions of fly ash at 10%, 30%, and 50%, utilizing an experimental testing approach that includes a static load compression test. The purpose of the compression testing apparatus is to ascertain the compressive strength characteristics and the mass percentage of the materials. The findings revealed that the maximum compressive strength achieved with 10% fly ash was 34.07 MPa; however, variations in the fly ash composition led to a reduction in the material's toughness properties by 10.42% and 16.53%, respectively. The recorded compressive strength values comply with the quality standards set forth in SNI 03-0691-1996 for paving blocks classified as type B quality. Furthermore, the variations in composition positively influenced the mass percentage, with considerable increases of 66.67% and 45.33% corresponding to the differing fly ash compositions.

Contribution to the Prediction of the Recycling Potential of Recycled Concrete as a Cement Admixture Based on the Compressive Strength of the Parent Concrete

When processing construction and demolition waste, determining the most effective waste management, potential use and recycling method for the identified materials is a key element. To do this, it is necessary not only to determine the type of materials, but also knowledge which aspects of the quality of the original materials are relevant for recycling and the ability to determine the values of these parameters as easily and quickly as possible, directly during demolition activities, is highlighted as an effective tool. This paper, intended as a case study, focuses on the evaluation of the effect of finely ground parent concrete as a cement component, the main objective being to find out whether the differentiation of the quality of the parent concrete, by compressive strength, plays a significant role. The parent concrete, the powder prepared from it, and the new standard mortar mixes, were analysed to obtain a comprehensive picture of the possibility of predicting the properties of the mixes based on the strength of the parent concrete. In general, no clear effect of the parent concrete strength on the flexural strength, compressive strength, water absorption, and ultrasonic pulse velocity values of the new generation mortar was observed. However, finely ground recycled concrete have shown a nice potential to be incorporated in Portland fine-grain cements, reaching strength classes 32.5 and 42.5. Care and precise verification require a 25% replacement, especially in the case of low strength parent concrete.

Rancangan kemasan pelindung apel selama tranportasi berbahan dasar eceng gondok dan sabut kelapa

Packaging during the transportation process greatly influences the damage to horticultural products. Harvest apples are usually packed in wooden boxes or bamboo baskets and stacked until they reach maximum capacity. This makes the fruit easily damaged by bruising due to high piles. Based on these conditions, it is necessary to handle horticultural products in the form of apples to reduce damage to the fruit during transportation to maintain the quality of the apples until they reach consumers and extend the shelf life of the fruit. This research aims to design protective packaging for apples from a combination of water hyacinth and coconut fiber. The experimental method was carried out in this research with 2 factors consisting of 3 levels; factor one the combination of packaging materials, and factor two was the pressure of the packaging printer. Nine experimental units were obtained from the combination of the two treatments, namely K1T1 (E 90% + S 10%) with a pressing pressure of 400 psi, K1T1 (E 90% + S 10%) with a pressing pressure of 700 psi, K1T1 (E 90% + S 10% ) with a pressing pressure of 1000 psi, K2T1 (E 60% + S 40%) with a pressing pressure of 400 psi, K2T2 (E 60% + S 40%) with a pressing pressure of 700 psi, K2T3 (E 60% + S 40%) with pressing pressure 1000 psi, K3T1 (E 30% + S 70%) with pressing pressure 400 psi, K3T2 (E 30% + S 70%) with pressing pressure 700 psi, K3T3 (E 30% + S 70%) with pressing pressure 1000 psi. The results showed that the combination treatment of K2T2 with a pressing pressure of 700 psi provided the best protective quality for apples with the lowest percentage of mechanical damage and reduction in apple mass, at 5.556%, 2.55%, respectively. The springiness and texture values for apples were the highest with values respectively 3.17 mm, 16.7335N. Meanwhile, the highest packaging compressive strength value was obtained in the K3T3 treatment with a value of 26.164N.

Modelling and evaluation of mechanical performance and environmental impacts of sustainable concretes using a multi-objective optimization based innovative interpretable artificial intelligence method

This study focuses on modelling sustainable concretes' mechanical and environmental properties with interpretable artificial intelligence-based automated rule extraction, management of waste materials, and meeting future prospects. In this context, 24 sustainable concrete series containing fly ash and recycled aggregates were produced. Compressive strength tests were performed on these specimens at 7, 28, and 90 days, and their mechanical properties were evaluated. Concrete classes (Class A, B, C, D) were determined using the compressive strength values obtained for each test day. The results of each concrete class were analyzed using a unique interpretable multi-objective rule extraction model, and the range values of the materials used were determined. The applied multi-objective rule extraction method is used for the first time in the literature, and its most important novelty is that, unlike other black-box artificial intelligence methods, it can also enable the creation of sustainable concrete recipes. After the range values of the materials used were found by automatic rule extraction, environmental impact assessments were performed. Among the impact categories, energy consumption and global warming potential were considered. The energy consumption results for Rule 4 were calculated as 814.8–1467.1 MJ, respectively, and a reduction of approximately 44.5% was observed. Similarly, global warming potentials for Rule 3 were obtained as 187.0–267.3 kg m3, respectively, with a reduction of about 30%. The limitations and future prospects of the study have been extensively investigated. The importance of adopting explainable/interpretable artificial intelligence-based approaches within the scope of sustainable development and circular economy goals to develop social infrastructure and buildings with low carbon emissions that are feasible in terms of mechanical and environmental properties is highlighted. Multi-Objective Optimization Based Innovative Interpretable Artificial Intelligence Method, used for the first time in mechanical and environmental modelling of sustainable concretes, can make significant contributions to the literature and future studies.

Mechanical properties of high-volume fly ash concrete with varying fly ash content

Fly ash is widely used as a replacement for cement to produce more environmentally friendly concrete with reliable performance in construction applications. Therefore, this research aimed to analyze the mechanical properties of high-volume fly ash concrete (HVFAC) using class F fly ash with different percentages. Performance tests that were carried out included workability, unit weight, and compressive strength. Laboratory experiments were conducted by making 5 variations of mix design, namely variation 1 (FA0), which consisted of normal concrete with a control test material of 100% Portland cement. The other 4 variations were HVFAC (FA70, FA80, FA90, and FA100), which were made with fly ash content comprising 70%, 80%, 90%, and 100% of the total binders/cementitious. Fresh concrete was tested for workability, while hardened concrete was tested for unit weight and compressive strength at ages 3, 7, and 28 days on test specimens subjected to water immersion curing. The results showed that all workability of HVFAC test specimens met the self-consolidated concrete (SCC) category. The dry unit weight of all specimens met the requirements for normal-weight concrete. The results of the compressive strength test at 28 days showed that the addition of fly ash percentage caused a decrease in the compressive strength value of the entire HVFAC, but still exceeded the minimum requirements for high-quality concrete. HVFAC with variations FA70, FA80, and FA90 met the requirements of ASTM C618-12a based on the evaluation of Strength Activity Index (SAI) values at 7 and 28 days of age, while FA100 did not meet the requirements.

Experimental investigation on the mechanical properties of Ti6Al4V cellular structures produced with selective laser melting: Effects of rib thickness, unit cell type and orientation

The objective of this study is to investigate the mechanical performance of Ti6Al4V cellular structures, including different unit cell forms such as honeycomb, re-entrant, hybrid (honeycomb + re-entrant), and chiral structures manufactured with selective laser melting. The study examines the influence of rib thickness and unit cell orientation on compressive strength, elasticity modulus, Poisson's ratio, energy absorption, and specific energy absorption. Increasing the rib thickness of the unit cells improved not only the compressive strength and elasticity modulus of the samples but also their energy absorption capacities. The mechanical properties of the cellular structures varied with changes in unit cell orientation, and no direct relationship was found. The highest values for compressive strength, energy absorption, and specific energy absorption were observed in re-entrant structures, while hybrid structures had the highest elasticity modulus values. It was also found that chiral structures had the lowest compressive strength, modulus of elasticity and energy absorption capacity of all the parameters investigated. In addition, re-entrant structures with negative Poisson's ratio tend to perform positive Poisson’s ratio when they are subjected to deformation under compression. The elasticity modulus of the biocompatible Ti6Al4V cellular structures is similar to that of femoral bone values. These structures meet the requirements for use in the core of implants. The results obtained from this experimental study may guide researchers in the field of biomechanics.

Evaluation of the Changes in the Strength of Clay Reinforced with Basalt Fiber Using Artificial Neural Network Model

In this research, the impact of basalt fiber reinforcement on the unconfined compressive strength of clay soils was experimentally analyzed, and the collected data were utilized in an artificial neural network (ANN) to predict the unconfined compressive strength based on the basalt fiber reinforcement ratio and length. For this purpose, two different lengths of basalt fiber (6 mm and 12 mm) were added to unreinforced bentonite clay at ratios of 0%, 1%, 2%, 3%, 4%, and 5%, and unconfined compressive tests were performed on the prepared reinforced clay samples to determine the unconfined compressive strength (qu) values. The evaluation of the obtained experimental results was carried out by creating ANN models. To validate the prediction capabilities of the ANN, a comparative analysis was performed using linear regression, support vector machines, and Gaussian process regression models. Ultimately, a five-fold cross-validation technique was employed to objectively evaluate the overall performance of the model. The evaluations revealed that the ANN model predictions using data obtained from experimental studies showed the highest accuracy and were in close agreement with the experimental results.

Investigating the influence of ferric oxide grade alumino‐silicate cenosphere particulates and heat treatment on the microstructural evolution and mechanical properties of Al6061/ferric oxide alumino‐silicate cenosphere (x weight %) composite

AbstractThe main aim of this investigation is to fabricate aluminum 6061 composites with three different weight percentages of ferric oxide grade alumino silicate cenosphere (1 wt.%, 3 wt.%, and wt.%) by the stir‐casting process. The fabricated cast composite and T6 heat‐treated composite is used to obtain a fundamental understanding of various weight percentages of the cenosphere and the influence of heat treatment on the microstructural changes, mechanical characteristics, the mechanism of fracture, and the interface between the aluminum‐matrix and ferric oxide grade alumino‐silicate cenosphere particulates. Tensile and compressive tests with a constant strain rate (0.5 mm ⋅ min−1) were carried out to study the strength and to find a correlation between the various weight fractions of cenosphere and heat treatment. Investigations of the changes in the microstructure of the aluminum ferric oxide grade alumino silicate cenosphere composite and the fractography of the fracture surface are investigated using optical and scanning electron microscope. X‐ray diffraction was utilized to confirm the results obtained from optical and scanning electron microscope analyses for phase characterization validation. A maximum of 30 % increase in hardness value, 20 % increase in tensile strength value, 33 % increase in maximum compressive strength value, and 2 % increase in elongation values are observed in heat‐treated composite when compared to cast composite.

Bioactive Compounds Enhance the Biocompatibility and the Physical Properties of a Glass Ionomer Cement.

In order to characterize a novel restorative material, knowledge about the toxicological effect on human cells and the physical behavior of a glass ionomer cement (GIC) containing flavonoids was established. The flavonoids apigenin, naringenin, quercetin, and liquiritigenin were manually incorporated into a GIC. In the control group, no incorporation was performed. Two cell culture assays evaluated the toxicity of GICs: SRB and MTT. For both assays, the keratinocyte cell line (HaCaT) was exposed to GIC (n = 3/group) for 24 h. The physical properties of the GICs were evaluated by compressive strength (n = 10), surface roughness (n = 10), and hardness (n = 10) tests. Cell viability by SRB ranged from 103% to 97%. The control revealed a significant decrease in the metabolism of cells (61%) by MTT, while the GIC+apigenin slightly increased the succinic dehydrogenase activity (105%; p > 0.05), also confirmed microscopically. The compressive strength and roughness values were similar among groups, but the hardness increased after the incorporation of naringenin and quercetin into GIC (p < 0.05). The incorporation of flavonoids positively altered the biological and physical properties of the GICs.