Compressive Strength Behavior Research Articles

VOLUME CHANGE AND COMPRESSIVE STRENGTH OF COMPACTED LATERITIC SOIL UNDER DRYING-WETTING CYCLE REPETITION

This study was conducted to investigate volume changes and compressive strength behavior of compacted high expansive soils from lateritic soils (60%) and bentonite (40%) mixture under drying-wetting cycle repetition as a construction materials alternatives. Lateritic soil obtained from waste Nickel mining site in East Halmahera, North Maluku, Indonesia. Laboratory tests of physical properties using ASTM standard test were conducted to lateritic soil, bentonite, and mixture soil, while SEM test for lateritic and mixture soil. The soil samples have optimum moisture content based on Proctor standard compaction test results (28%). Then, samples were treated drying-wetting cycle and repeating four cycles with 25, 50, 75, and 100% series path. The soil suction measurement used the Whatman #42 filter paper placed at the top, middle, and bottom of each sample, and after that, the unconfined compression strength test was performed based on the ASTM standard. The experimental results showed that the drying-wetting cycle repetition has a significant effect on volume change, suction, and compressive strength of the soil. The increasing number of cycle causing void ratio decrease and degree of saturation increase, and soil suction tend to decrease at the certain void ratio; likewise, soil compressive strength decreases at particular water content. Decreasing soil compressive strength causes a decrease in elastic modulus so that soil failure behavior is more brittle and work-softening. Therefore, the study results provide important geotechnical characteristics data of lateritic soil with high swell-shrink potential. Henceforth, some soil improvement innovations can perform to generate high-quality construction materials more effectively and efficiently.

Predicting strength of soilbags under cyclic compression

Soilbags have a wide range of applications in geotechnical engineering. To explore the compressive strength and deformation behaviour of soilbags, a formula for predicting the strength of soilbags is derived considering the relationship between the tensile force of the bag and the vertical strain. A soilbag under cyclic compression is numerically simulated using the discrete element method to verify the basic stress formula and the derived formula for the tensile force. The results indicate that the increase and distribution of the tensile force in the bag material have an important effect on the compressive strength of soilbags. The derived formula can predict the compressive strength of soilbags under vertical loading, providing a theoretical basis and design methods for structures built with soilbags.

Compressive strength and durability behavior of graphene oxide reinforced concrete composites containing recycled concrete aggregate

Compressive strength and durability behavior of graphene oxide reinforced concrete composites containing recycled concrete aggregate

Engineering properties of strain hardening geopolymer composites with hybrid polyvinyl alcohol and recycled steel fibres

Engineering properties of strain hardening geopolymer composites with hybrid polyvinyl alcohol and recycled steel fibres

Utilization of fly ash amended sewage sludge as brick for sustainable building material with special emphasis on dimensional effect

Utilization of fly ash amended sewage sludge as brick for sustainable building material with special emphasis on dimensional effect

The synergic influence of carbon nanotube and nanosilica on the compressive strength of lightweight concrete

The synergic influence of carbon nanotube and nanosilica on the compressive strength of lightweight concrete

Recovery of Biomass Fly Ash and HDPE in Innovative Synthetic Lightweight Aggregates for Sustainable Geotechnical Applications

Sustainable development principles aim to re-utilize wastes to reduce their impact on the environment. In this context, the present contribution shows preliminary results on the preparation of innovative synthetic lightweight aggregates, starting from biomass-derived fly ash and high-density polyethylene (HDPE), to be used in geotechnical applications. The present work focuses on the manufacturing process of aggregate blends (including the selection of the right proportions of the two components) as well as on the relative determination of (i) physical–chemical properties (i.e., chemical composition, morphological analysis, mineral leachability, water absorption, specific gravity, grain size distribution); (ii) permeability features and (iii) mechanical properties (one-dimensional compression and shear strength behavior). The results, gathered from the new synthetic lightweight aggregates and compared with the corresponding ones obtained in a previous study conducted on natural and synthetic lightweight aggregates, appear promising for a potential utilization in geotechnical engineering.

Ultimate Compressive Strength of Stiffened Panel: An Empirical Formulation for Flat-Bar Type

This research aims to study the ultimate limit state (ULS) behaviour of stiffened panel under longitudinal compression by a non-linear finite element method (NLFEM). There are different types of stiffeners mainly being used in shipbuilding, i.e., T-bar, flat-bar, and angle-bar. However, this research focuses on the ultimate compressive strength behaviour of flat-bar stiffened panel. A total of 420 reliable scenarios of flat-bar stiffened panel were selected for numerical simulation by the ANSYS NLFEM. The ultimate strength behaviours obtained were used as data for the development of closed form shape empirical formulation. Recently, our group proposed an advanced empirical formulation for T-bar stiffened panel, and the applicability of the proposed formulation to flat-bar stiffened panel is confirmed by this study. The accuracy of the empirical formulation obtained for flat-bar stiffened panel was validated by finite element (FE) simulation results of statistical analysis (R2 = 0.9435). The outcome obtained will be useful for ship structural designers in predicting the ultimate strength performance of flat-bar type stiffened panel under longitudinal compression.

Compressive Strength and Shrinkage Behavior of Concrete Produced from Portland Limestone Cement with Water Absorption Polymer Balls

From the sustainability point of view a combination of using water absorption polymer balls in concrete mix produce from Portland limestone cement (IL) is worth to be perceived. Compressive strength and drying shrinkage behavior for the mixes of concrete prepared by Ordinary Portland Cement (O.P.C) and Portland limestone cement (IL) were investigated in this research. Water absorbent polymer balls (WAPB) are innovative module in producing building materials due to the internal curing which eliminates autogenous shrinkage, enhances the strength at early age, improve the durability, give higher compressive strength at early age, and reduce the effect of insufficient external curing. Polymer balls (WAPB) had been used in the mixes of this research to provide good progress in compressive strength with time. Water absorption polymer balls have the ability to absorb water and after usage in concrete it will spill it out and shrink leaving voids of their own diameter before shrinking that lead to provide internal curing. The required quantity of water for the mixes were reduced due to the addition of water from the absorption polymers. Mixes produced from Portland limestone cement in this research show drying shrinkage results and compressive strength results lower than mixes made from ordinary Portland cement.

Long term evaluation of engineered cementitious composite containing stone slurry powder

Long term evaluation of engineered cementitious composite containing stone slurry powder

A comparative study on the implementation of carbon and glass fibers wrappings to improve the compressive strength and seismic behavior of concrete

Fiber-reinforced polymer (FRP) wrapping is one of the current approaches for retrofitting projects. This study aims to compare the performance of carbon and glass fibers in increase of compressive strength and improvement of concrete seismic parameters. In this research, three classes of concrete compressive strength (20, 35, and 50 MPa) are considered. The samples are warped with 0, 1, 3, and 5 layers of both fibers and examined under stress–strain tests. The results show that by adding more FRP layers, an increase is seen in compressive strength and seismic parameters. However, their growth rates decline. Moreover, the effect of both types of fibers is greater on improvement of compressive strength and failure strain for higher strength concrete. In contrast, fibers are more influential on lower strength concrete regarding energy absorption and ductility. Carbon and glass fibers are more effective in enhancing of compressive strength and seismic parameters, respectively. Statistical analysis indicates that, by adding more FRP layers, a tangible improvement on compressive strength and seismic parameters of concrete can be observed. That is true, especially for lower strength concrete. Moreover, the results demonstrate that the effect of fibers on the mentioned quantities is generally more than the effect of concrete classes. Finally, the Lam & Teng model shows a good fit with the experimental stress–strain diagrams.

Compressive Properties of A356 Closed-Cell Aluminum Foamed with a CaCO3 Foaming Agent Without Stabilizer Particles

The A356 aluminum alloy foams were fabricated by the melt foaming method using a CaCO3 foaming agent without any stabilizer particle. The samples of different densities ranging from 0.32 to 0.46 g/cm3 (relative densities of 0.12–0.17, respectively) and cell sizes ranging from 1.5 to 3.1 mm were formed. The effect of foaming conditions such as CaCO3 amount, mixing and holding time on compressive strength and energy absorption behavior were investigated. Results show that the compressive properties of the aluminum foam are characterized by three deformation stages: linear elastic stage, plastic collapse stage and densification stage. Also, the compressive stress and energy absorption capacity increase as the relative density increases. But elastic modulus of the foamed aluminum with 3 wt% CaCO3 (relative density = 14%) is higher than others because its cell size distribution is more homogeneous than others. The compressive strength of aluminum foams without any stabilizer particles is comparable to the other researches for aluminum foams with stabilizer particles at the same density.

Compaction delay and its effect on the geotechnical properties of lime treated semi-arid soils

Quality construction control requires ensuring that compacted fills are properly placed without any significant delay between mixing and compaction of the wet soil mixture. When chemical treatment is resorted to meet the shortcomings in the use of locally available materials, the delay in compaction (time elapsed between mixing and compaction of the wet soil mixture) plays a significant role as it dictates the final in-site density values achieved. In this study, the effect of delay in compaction on the density and moisture content relationships was evaluated for the delay periods of 1hr, 4hr, 24 hr and 7 days. The study was even extended to lime treated soils (at 2% and 4% by dry weight of soil). The time lag which occurs immediately after the onset of wet mixing and compaction often results in variation in geotechnical properties. Accordingly, an attempt was also made to study the effect of delay in compaction on the hydraulic conductivity, compressibility and unconfined compressive strength (UCS) behaviour of plastic clays sourced from the semi-arid region. In order to understand the variations in microstructure, MIP tests (Mercury Intrusion Porosimetry) were conducted at higher delay periods when treated with lime. From the results, it was observed that delay in compaction led to an increase in the hydraulic conductivity and compressibility of both soils. Furthermore, the UCS of both the soils showed a decreasing trend with the increase in the delay period. The agglomeration of clay particles leads to the formation of clods at higher delay periods which resist the compaction energy resulting in reduced density values which in-turn affect the geotechnical properties.

The compressive strength behavior of mahogany wood connections with bolt-ring connectors

The connection systems of wood structures, which are often observed in Indonesia, mainly utilize bolts or nails, whereas a similar system with bolt-ring connectors is quite rare. In fact, in other countries like U.S., Netherlands, etc., such a system is commonly implemented, especially for the constructions of wood buildings which require a large capacity or a relatively large building. To show that the system also potentially excels when used for wood materials in Indonesia, especially in comparison with the ordinary bolt connection system, several empirical tests of the connection systems with materials from Mahogany wood (Swietenia spp.) were conducted. This experiment implemented six connection systems under compressive tests in order to investigate the compressive strength behavior of bolt-ring connections compared with the bolt connections. From this study, it can be concluded that the bolt-ring connection system yields better compressive strength behavior and performance than the bolt connection system. However, if used in connections with single ring, it is necessary to be careful when they are subjected to compressive loads. It is due to the connection system which may undergo rotations which can cause the system to be unstable. If stability can be safely maintained by adding some steel plate holder; then, the system will become more superior to the simple bolt connection system, in terms of compressive strength, stiffness, and ductility.

Effect of wastes and admixtures on compressive strength of concrete

PurposeThis paper presents the effects of replacing fine aggregate (FA) with waste foundry sand (WFS) in natural aggregate and construction waste aggregate concrete specimens without and with superplasticizer (SP), silica fume (SF) and fiber (F) to solve the disposal problems of various wastes along with saving the environment. This study aims to investigate the effect of construction waste, WFS along with additives on the stress-strain behavior and development of compressive strength with age.Design/methodology/approachThe various concrete specimen were prepared in mix proportion of 1: 2: 4 (cement (C): sand: coarse aggregate). The water-cement ratio of 0.5 (decreased by 10% for samples containing SP) to grading 1: 2: 4 under air-dry condition was adopted in the preparation of concrete specimens. The compressive strength of various concrete specimen were noticed for 3, 7 and 28 days by applying load through universal testing machine.FindingsUpon adding construction and demolition waste aggregates, the compressive strength of concrete after 28 days was comparable to that of the control concrete specimen. An enhancement in the value of compressive strength is perceived when FA is replaced with WFS to the extent of 10%, 20% and 30%. If both construction and demolition waste aggregate and WFS replacing FA are used, the compressive strength increases. When FA is interchanged with WFS in natural aggregate or construction demolition waste aggregate concrete including usage of SF or F, the compressive strength improves significantly. Further, when construction and demolition waste aggregate and WFS replacing FA including SP are used, the compressive strength improves marginally compared to that of control specimen. The rate of strength development with age is observed to follow similar trend as in control concrete specimen. Therefore, construction and demolition waste and or WFS can be used effectively in concrete confirming an improvement in strength.Originality/valueThe utilization of these wastes in concrete will resolve the problem of their disposal and save the environment.

Mechanical behavior, acoustic emission properties and damage evolution of cemented paste backfill considering structural feature

Mechanical behavior, acoustic emission properties and damage evolution of cemented paste backfill considering structural feature

Mechanical and Fiber-Bridging Behavior of Slag-Based Composite with High Tensile Ductility

This paper presents an experimental and analytical investigation of the fundamental mechanism of the highly ductile behavior of strain-hardening slag-based composite reinforced by polyethylene fibers. Composite properties, including compressive strength and tensile behavior of the composite, were identified. Micromechanical characteristics, including matrix fracture toughness and interfacial properties between matrix and fiber, were investigated and the fiber-bridging behavior of the composite was simulated. The tensile behavior of the composite was evaluated by micromechanical analysis. Test results showed that the composite had extremely high tensile ductility of up to 7.5% and high tensile strength of 8.5 MPa, along with a moderate compressive strength of 36.8 MPa. Saturated cracking patterns with controlled crack width of 59.8 μm were also observed in the composite. Considering the variation of matrix properties and fiber distribution, the theoretical fiber-bridging curve simulated the tensile behavior of the composite well, and the micromechanical analysis results supported the tensile behavior of the composite.

Strength studies on geopolymer concrete with GGBS and Fly ash

Geopolymer concrete is a pollution controlled and eco-friendly alternate material used for construction in the recent years. This concrete has many advantages and applications. The main aim of this study is to check the effect of Fly ash and Ground Granulated Blast Furnace Slag (GGBS) on the mechanical properties of Geopolymer concrete at different replacement levels of GGBS by fly ash from 0 to 25% with 5% variation. From previous researches on Geopolymer concrete, an optimized mix is identified for testing mechanical behaviour. Sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) of 12 Molarity is used as activator solution in the ratio of 1:2.5. A carboxylic based admixture called La Hypercrete S25 is added in the mix by 1% of the weight of GGBS for increasing the workability of Geopolymer concrete. Cubes of 100mm size are cast for determining the compression strength behavior. Cylinders of 100mm dia and 200mm height are cast for splitting tensile strength and beams of size 500mm length with 100mm x 100mm cross section are cast for flexural strength. The specimens are cured at ambient temperature and tested on 7 and 28 days. The test result shows the strengths gradually increases for 5, 10, 15 and 20% replacement of GGBS by fly ash. The maximum values are obtained for 20% of GGBS replacement by flyash in all the tests. The strengths reduce for replacements of above 20%. This study concludes that geopolymer concrete performs well in strength properties with GGBS and Fly ash.

Development of ultra-high performance geopolymer concrete (UHPGC): Influence of steel fiber on mechanical properties

Development of ultra-high performance geopolymer concrete (UHPGC): Influence of steel fiber on mechanical properties

The effect of strut size on microstructure and compressive strength of porous Ti6Al4V lattices printed via Direct Ink Writing

The effect of strut size on microstructure and compressive strength of porous Ti6Al4V lattices printed via Direct Ink Writing