Slump Flow Research Articles

Effect of sand fineness modulus on SCC and SCLC properties

Due to the advantageous characteristics of self-compacting concrete (SCC) and self-compacting lightweight concrete (SCLC), the advancement of the SCC is considered a remarkable engineering feat. Fine aggregate is one of the main parameters of SCC; however, its effect on SCC and SCLC properties is somewhat restricted due to the limited extent of in-depth research conducted in this field. To investigate the effect of changes in sand fineness modulus (FM) on the fresh and hardened properties of SCC and SCLC, an experimental investigation with twelve mixtures was designed. Two series of mixtures were used, each with two coarse aggregate types: Light Expanded Clay Aggregate (LECA) and natural gravel. Each series included different sand FM (2.3, 2.7, and 3.1), with the incorporation of 7% micro-silica (MS) as a cement substitute in some designs. The fresh properties of the concrete were evaluated through tests such as Slump Flow, V-Funnel, U-box, L-Box, and J-Ring, in addition to the Static Segregation Column test. For evaluating the hardened properties, 192 specimens were tested, including compressive, tensile, and flexural specimens. Moreover, fracture energy was also investigated. As the sand FM increased, it was expected that the fresh properties of concrete might decrease due to coarser aggregate volume, and the hardened properties would improve under these conditions. However, the results showed that increasing the sand FM improved the fresh and hardened properties of SCC and SCLC. By increasing the sand FM, the flowability, filling ability, and passing ability of both concrete improved, but on the other hand, elevating the sand FM reduced the segregation resistance of the mixes. In contrast, the hardened properties exhibited contrasting outcomes with increasing the sand FM. Increasing the sand FM improved the compressive strength by about 20% in both concrete types.

The Influence of Mineral Additives and Sands on the Performance of Self-Compacting Sand Concretes

Abstract The chosen plan for our case study is a network mixture design consisting of 21 mixtures. The application of this method has proven to be immensely useful in studying the influence of composition parameters (composite design) and the utilization of various types of mineral additives (mixture design). The application of the Design of Experiments (DOE) method, based on a statistical approach, allowed for a better understanding of the effect of formulation parameters, including the proportion of alluvial sand (75%), dune sand (25%), the total amount of sand kept at constant percentages, the dosages of brick powder, limestone filler and ceramic powder (all varying from 0 %, 20 %, 40 %, 60 %, 80 %, and 100 %), while keeping the dosage of superplasticizer and the water/binder ratio constant. This approach helped to understand the interactions between these parameters and their impact on the process. Mathematical models relating the variations of these parameters to the workability and compressive strength of such concrete mixtures have been established. The results obtained show that the workability of SCSC (expressed by slump flow and V-funnel flow) improves with the increase in the dosage of limestone filler (FC), brick powder (PB), and ceramic powder (PC), with element having a different impact, be it alone or in a combination. Moreover, they all improved the behavior of SCSC in both the fresh and hardened states. The experiment shows that increasing the proportions of FC and PC in the mixture, whether linear, binary, or ternary, leads to a significant improvement in compressive strength. Furthermore, better strength is observed in the ternary mixture at 28 days, with a strength of 43 MPa, with the following proportions (FC 70%, PB 20%, PC 10%). Finally, the result at 180 days of 48 MPa confirms the following proportions (PC 60 %, FC 30 %, PB 10 %) The compliance of some SCSC compositions was tested according to the recommendations of the French Association of Civil Engineering.

Investigating Some Properties of Hybrid Fiber Reinforced LECA Lightweight Self-Compacting Concrete

. The primary goal of this investigation is to study the effect of using mono and hybrid fibers on the fresh and hardened characteristics of Lightweight Self-Compacting Concrete (LWSCC). Slump flow test, L-box test, sieve segregation test, and V-funnel test were used to evaluate the workability of LWSCC. The mechanical characteristics of LWSCC were assessed by using compressive strength, splitting strength, and flexural strength. Four mixtures using two types of fiber: Steel fiber (St) and polypropylene fiber (PP) (0% fiber, 1% (St), 0.75% (St) +0.25% (PP), 0.5% (St) +0.5% (PP)) were made. According to the results, (St) fiber and hybrid fiber addition to LWSCC reduced its workability, although the values of tests were still within the acceptable range stander of EFNARC. The findings indicated a decrease in the values of slump flow and L-box test by adding mono and hybrid fibers to the LWSCC mixture. While the T500mm and V_ funnel tests increased by adding mono and hybrid fibers to LWSCC mixture. The results also indicate that the utilisation of (St) fiber and hybrid fibers had a significant effect on the mechanical characteristics of LWSCC. Where the flexural and splitting strengths significantly increase with the addition of (St) and hybrid fibers to the LWSCC mix.

Optimization of recycled rubber self-compacting concrete: Experimental findings and machine learning-based evaluation

This research aims to assess the rheological and mechanical characteristics of Self-compacting concrete (SCC) incorporating waste tire rubber aggregates (WRTA) as an interim substitute for coarse aggregates. However, the standard experimental modeling approach has significant obstacles when it comes to overcoming the nonlinearity and environmental susceptibility of concrete parts. Therefore, linear regression (LR) and extreme gradient boosting (XGBoost) were used as two standard single machine learning (ML) models to predict the aforementioned rubberized SCC features. In this study, conventional coarse aggregates were supplanted with WRTA at 0%, 5%, 10%, and 20% to uncover the optimal proportion of coarse aggregates substituting rubber. To find the optimum amount of WRTA to use as a substitute, the study follows the impacts of rubber on the self-compacting rubberized concrete's (SCRC) rheological and mechanical characteristics. The consequences on fresh properties were investigated by the slump flow, J-ring, and V-funnel tests, while compressive and splitting tensile strengths tests were conducted to assess mechanical properties. Increasing WRTA test outputs indicated a deterioration in workability and hardened qualities. While a 10% swapping ratio is deemed feasible for producing SCRC, optimal results were achieved by reducing environmental impacts and efficiently managing a significant volume of rubber tire waste with a 5% substitution of rubber within the coarse aggregates. The research findings indicated a noticeable decrease in fresh properties as the WRTA content increased. Notably, after 28 days, a 10% WRTA substitution led to a 34% reduction in compressive strength and a 28% decrease in splitting tensile strength, satisfying ACI standards. Furthermore, XGBoost demonstrated superior predictive performance with the highest R2 values, outperforming the LR model and affirming its efficacy in delivering more accurate predictions.

Modeling the Properties of Sustainable Self-Compacting Concrete Containing Marble and Glass Powder Wastes Using Response Surface Methodology

This study aims to apply the response surface methodology (RSM) to develop a statistical model that predicts and models the performance of both the fresh and hardened properties of self-compacting concrete (SCC). RSM was used to model processes involving three variables: the water/binder ratio, and the percentages of waste marble, and glass powder. Tests, including slump flow diameter, sieve stability, and L-box, were carried out to evaluate the fresh properties of the self-compacting concrete; compressive strength was analyzed at 7, 28, and 90 days. Statistical significance was only observed in the water/binder ratio for both the slump flow and sieve stability tests. Furthermore, these results indicate that the models used in the compressive strength tests demonstrate a high statistical significance for all ages. The findings suggest that incorporating waste marble powder (MP) and glass powder (GP) in SCC necessitates a significant amount of superplasticizer to counteract the workability loss, and it improves the compressive strength of SCC. The coefficients analyzed using the RSM approach validate its effectiveness as a predictive tool for determining the hardened properties of self-compacting concrete.

REVIEW OF THE EFFECT OF INDUSTRIAL WASTE ON SELF COMPACTING CONCRETE

Self-Compacting Concrete (SCC) is an innovation in concrete technology used in building elements with dense and complex reinforcement frameworks. SCC is characterized by its high fluidity and the ability to self-compact without the use of vibrators. Superplasticizer is one of the components applied in the production of SCC. The use of superplasticizer aims to reduce water consumption, accelerate the setting time, improve concrete workability, and also make the concrete impermeable.
 As time progresses, industrial waste continues to increase, highlighting the importance of recycling industrial waste. The purpose of this research is to investigate the influence of industrial waste as a substitute material for fine aggregates on the workability and compressive strength of SCC. This study is the result of a literature review obtained by examining various sources including books, proceedings, as well as international and national journals.
 The results of this literature study involve the use of industrial waste materials such as recycled glass, granite waste, nickel slag, and copper slag as substitutes for fine aggregates. The results of the workability and compressive strength of SCC are influenced by the characteristics of each industrial waste used. This indicates an improvement in the flowability (slump flow) with an increasing percentage of industrial waste, ranging from 0% to 60%, in the concrete composition.
 Compressive strength test results indicate that the optimal percentage of industrial waste addition in the concrete composition lies between 20% and 40%."

Enhancing Sulfate Erosion Resistance in Ultra-High-Performance Concrete through Mix Design Optimization Using the Modified Andreasen and Andersen Method

This study presents an in-depth investigation into optimizing the mix design of ultra-high-performance concrete (UHPC) for enhanced sulfate erosion resistance, utilizing the modified Andreasen and Andersen (MAA) method. By testing the mechanical properties and slump flow of UHPC, it was determined that the optimal W/B = 0.2, and the best volume content of steel fibers is 2%. Through long-term tests lasting 360 days on three groups of UHPC specimens under different curing conditions, their mass loss, compressive strength corrosion resistance coefficient, surface appearance, and erosion layer thickness were tested. The results indicate that under sulfate attack, the mass and compressive strength corrosion resistance coefficients of UHPC specimens showed a trend of first increasing and then decreasing, due to the formation and expansion of ettringite and gypsum. The thickness of the erosion layer increases over time. By 360 days, the internal damage caused by sulfate attack is about twice as severe as it was after 60 days. However, the addition of steel fibers was found to effectively mitigate these effects, reducing mass loss and preserving the structural integrity of UHPC.

Inovasi Teknologi Beton Self Compacting Concrete Terhadap Panjang Pengaliran (L-Flow) Dengan Variasi Umur Perawatan Beton

The aim of this research is to analyze the effect of adding hyperplasticizer and retarder on the compressive strength of self-compacting concrete. Fine aggregate and coarse aggregate from the Jenneberang River, Kab. Gowa. The concrete mix design uses a trial and error mix design for self-compacting concrete by making visual observations, so that the physical conditions of the mixture appear to be sufficient to produce a good mix. The stages of this research, by finding a comparison of the slump flow values ​​of the self-compacting Concrete concrete, then making test objects, after that curing the test objects using the water curing method for 28 days, then testing the compressive strength of the self-compacting Concrete concrete to produce comparison to the compressive strength of normal(conventional) concrete. The results of this research show that self-compacting concrete has a compressive strength value of 46.25 Mpa compared to normal concrete of 45.02 Mpa, an increase of 2.73% compared to normal concrete. And the slump value of normal concrete is 8 - 13 cm, while the slump flow of self-compacting concrete is 63 - 84.9 cm, with a time range between 2.53 - 3.46 seconds, able to reach a diameter of 500 mm on the segregation board.

Using the meta-heuristic algorithms to optimize the radial basis function for predicting high-performance concrete compressive strength and slump flow

Using the meta-heuristic algorithms to optimize the radial basis function for predicting high-performance concrete compressive strength and slump flow

Increasing the Length of Concrete Pavement Slabs Using Shrinkage Reducing Admixture and Polypropylene Fiber

Pavement engineers frequently employ concrete pavements because of their benefits such as extended lifetime, superior performance and durability, and so on. However, there are some disadvantages of these pavements such as shrinkage which may lead to cracking, warping, and limiting the length of the concrete pavement slabs. Shrinkage reducing admixture (SRA) and polypropylene fibers can be employed to prevent or control shrinkage cracking. In this study, increasing the length of concrete pavement slabs using shrinkage reducing admixture and polypropylene fiber was investigated. For mix compositions, two water–cement ratios of 0.35 and 0.4 were employed, and the percentages of SRA and polypropylene fiber utilized in mixes were 2% and 1% by weight of cement, respectively. Slump, compressive strength, third point flexural strength, electrical resistance, free and restrained shrinkage tests were carried out as the experimental programming to investigate the effect of these materials on concrete behavior and evaluate the amount of concrete pavement design parameters. Statistical analysis and RSM were used to determine the significance of each parameter and their interactions on concrete properties. It was observed that the use of SRA had no influence on workability; however, polypropylene fibers reduced the slump flow of concrete. Also, the use of SRA resulted in a decrease in mechanical properties. In addition, the use of polypropylene fibers considerably enhanced the energy absorption of concrete. Furthermore, on concrete containing SRA and polypropylene fiber, the magnitude of free and restrained shrinkage and crack width were reduced. Finally, the length and thickness of concrete pavement slabs were evaluated using the experimental results on the Tehran-Shomal freeway as a case study. The slab length could be increased by about 20% without any significant change in the slab thickness using SRA and polypropylene fiber in concrete mix composition. This can lead to an increase in construction speed, improve the durability of pavement and generally increase the quality of the concrete pavement.

Development of ultra-lightweight foamed concrete modified with silicon dioxide (SiO2) nanoparticles: Appraisal of transport, mechanical, thermal, and microstructural properties

Over the last few decades, researchers have devoted significant consideration to the use of nanoscale elements in concrete. Silicon dioxide nanoparticles (SDNs) have been a popular subject of study among the several types of nanoparticles. This article describes the findings of a laboratory investigation that examined the properties of ultra-lightweight foamed concrete (ULFC) including different proportions of SDNs. Wide range of the properties was evaluated specifically the slump flow, density, consistency, flexural strength, modulus of elasticity, compressive strength, split tensile strength, thermal properties, porosity, water absorption, sorptivity, intrinsic air permeability, and chloride diffusion. Additionally, the scanning electron microscopy (SEM) and pore distributions analyses of different mixes were done. Results confirmed a noticeable increase in the mechanical properties of ULFC, with respective improvements in the 28-day compressive, split tensile, and flexural strengths of up to 70.49%, 76.19%, and 51.51%, respectively, at 1.5% of the SDNs inclusion. However, further increases in the SDNs percentage did not result in remarkable enhancements. As the SDN percentage increased from 1.5% to 2.5%, the ULFC's sorptivity, porosity, water absorption, intrinsic air permeability, and chloride diffusion showed substantial improvements. When compared to the control sample, ULFC with SDNs demonstrated higher thermal conductivity values. The reason for this occurrence was determined to be the smaller pore size observed in the ULFC specimens containing SDNs. A great adjustment in the distribution of pore diameters was witnessed in the ULFC mixes when the percentages of SDNs were adjusted. The ULFC specimens, which included SDNs at the percentages of 0.5%, 1.0%, and 1.5%, indicated a reduction in the total number of large voids measuring 500 nm or more, compared to the control ULFC specimen. The findings of this study highlight the potential benefits of incorporating SDNs into ULFC, which may improve its overall properties.

Predicting the flowability of UHPC and identifying its significant influencing factors using an accurate ANN model

In this research, a one-hidden layer artificial neural network paradigm (ANN) was created to forecast the slump flow of ultra-high-performance concrete (UHPC). To achieve this goal, 3,200 ANNs were evaluated to estimate the fresh UHPC’s slump flow utilizing 793 observations. The performance metrics measured on training and test data subsets were in the same order of magnitude, thereby pointing out the proper work of the k-fold validation procedure. The results of the connection weight approach analysis (CWA) indicated that water dosage had the highest positive importance in slump flow, preceding the superplasticizer volume ratio. Other factors that positively influenced slump flow were the water-to-powder ratio, the dosage of high-alkali glass powder, the water-to-binder ratio, and limestone concentration. The most negative influences on rheology were the high-alumina FC3R and metakaolin. The ANN accurately predicted the slump flow of UHPC, while the results of the CWA analysis were well-correlated with previous research.

Design of self-compacting ultra-high performance concrete (SCUHPC) towards to the cementitious materials packing optimization

UHPC is a cement-based material characterized by outstanding strength and durability, but its high viscosity poses challenges for field application. Herein, we built a Horsfield theory modified cementitious packing structure by utilizing fly ash microsphere (FAM), aiming to release water, thus, reduce viscosity. The wet packing density indicated that FAM could optimize the packing structure, and transform locked water into free water. Meanwhile, 1H NMR revealed the variation of adsorbed water to free water due to the surface characteristics of FAM. Consequently, more free water could be obtained, which thereby reduced the viscosity up to 75 %. The slump flow, t500, v-funnel flow time and J-ring tests were further conducted to assess the workability, where the results indicated the modified UHPC met the standards for self-compacting concrete. Besides, the synergistic water-reducing strategy attributed to cementitious materials packing optimization can maintain a low w/b (<0.2), which contributes to an ultrahigh strength of 120.5 MPa, realizing the feasibility of developing self-compacting UHPC This study provides a new approach to enhance the workability of UHPC without sacrificing mechanical property and durability, expanding the field application of UHPC.

Optimization of rheological and mechanical properties of sustainable lateritic self-compacting concrete containing sisal fiber using response surface methodology

This study aims to identify effective methods for utilizing the percentage of waste laterite scraps as coarse aggregate through the optimization of performance-based sustainable lateritic self-compacting concrete. Thirteen mixes were made using RSM's central composite design (CCD), each with a unique combination of input factors (LA: 10–50 %, SF: 0.25–1.25 %), which were then tested for six responses (rheological properties: Slump flow (SF), V-funnel time (VT), and T500 strength characteristics: compressive strength, split tensile strength, and flexural strength). The ANOVA method was employed to evaluate the precision of the mathematical models created for the experiment. ANOVA was used to design and verify six response models (five quadratic and one linear). The analysis of variance results demonstrated the validity of each constructed model. Multi-objective optimization was used to study the interactions between the different components and determine the appropriate mixing ratio, resulting in an optimal percentage of LA and SF of the required characteristics without compromising the rheological and mechanical properties. Considering the goals of multi-objective optimization, the optimal LSCC produced with SF addition of 0.76 % and LA as a granite aggregate replacement of 26.8 %, yielding fresh properties of VT of 9.06 s, T500 of 2.26 s, and slump flow of 795.63 mm, and hardened properties of CS of 49.24 MPa, FS of 5.21 MPa and STS of 4.54 MPa. Experimental validation was carried out with an error rate of less than 5 % of the anticipated optimal data.

The Slump Flow of Cementitious Pastes: Simulation vs. Experiments.

Understanding the transient properties of cementitious pastes is crucial for construction materials engineering. Computational modeling, particularly through Computational Fluid Dynamics (CFD), offers a promising avenue to enhance our understanding of these properties. However, there are several numerical uncertainties that affect the accuracy of the simulations using CFD. This study focuses on evaluating the accuracy of CFD simulations in replicating slump flow tests for cementitious pastes by determining the impact of the numerical setup on the simulation accuracy and evaluates the transient, viscosity-dependent flows for different viscous pastes. Rheological input parameters were sourced from rheometric tests and Herschel-Bulkley regression of flow curves. We assessed spatial and temporal convergence and compared two regularization methods for the rheological model. Our findings reveal that temporal and spatial refinements significantly affected the final test results. Adjustments in simulation setups effectively reduced computational errors to less than four percent compared to experimental outcomes. The Papanastasiou regularization was found to be more accurate than the bi-viscosity model. Employing a slice geometry, rather than a full three-dimensional cone mesh, led to accurate results with decreased computational costs. The analysis of transient flow properties revealed the effect of the paste viscosity on the time- and shear-dependent flow progress. The study provides an enhanced understanding of transient flow patterns in cementitious pastes and presents a refined CFD model for simulating slump flow tests. These advancements contribute to improving the accuracy and efficiency of computational analyses in the field of cement and concrete flow, offering a benchmark for prospective analysis of transient flow cases.

Palm Oil Fuel Ash and Fly Ash for a Partial Replacement of Cement in High-Quality, Environmentally Friendly Mortar as a Solution to Industrial Waste

This study explores the effects of incorporating palm oil fuel ash (POFA) and fly ash (FA) as partial cement substitutes on the mechanical properties and characteristics of high-quality mortar, specifically Engineered Cementitious Composites (ECC). ECC mortar was fabricated by milling POFA waste and FA through a top-down method utilizing a ball mill. The resulting material was subjected to tests for slump flow, water absorption, compressive strength, and characterized through XRF, FTIR, SEM/EDX, and XRD analyses. FTIR analysis verified the existence of Si-O and Al-O groups within the composite made of POFA-FA ECC. XRF analysis of FA and POFA showed cementitious properties, with SiO2+Al2O3+Fe2O3 exceeding 50% and CaO surpassing 10%. SEM and XRD results indicated minimal cavity formation, suggesting a high compressive strength in the mortar. Particle size distribution analysis revealed prevalent particles in the 1.5×10−1 to 2.0×10−1 μm range. The compressive strength test after 28 days, incorporating 15% FA and 10% POFA, yielded the highest strength at 59.30 MPa. The water absorption values ranged from 1.25% to 2.67%, indicating that POFA-FA assists in the cement hydration process and also serves as a filler. As a result, the material’s density is very high, leading to fewer voids formed, thus reducing the trapped water, which significantly affects the mortar’s strength.

Effect of combination between hybrid fibers and rubber aggregate on rheological and mechanical properties of self-compacting concrete

Rubber aggregate recycled from waste tires are added to self-compacting concrete to improve some of its properties, such as durability, toughness, and concrete resistance to impact and vibrations. In this study, modified hybrid rubberized self-compacting concrete (SCC) was produced by utilization of recycled tire rubber aggregate, plastic waste (PET), and steel fibers. Rubber was used as a partial substitute for sand, with only 10%, while the fibers were utilized in two different proportions of 0.25% and 0.35% (volume). Several tests were achieved to evaluate the rheological properties of the modified hybrid fiber rubberized SCC such as slump flow, T500, V-funnel, L-box, and segregation resistance. In addition, the hardened properties such as density, compressive, tensile strengths, and modulus of elasticity were evaluated. Microstructural evaluation of rubberized mixes was conducted. The results showed that the addition of rubber aggregate at 10% content reduces the rheological properties of SCC. The T500 mm was influenced significantly up to 15% increase. Moreover, compressive strength decreased by about 14% at same amount of rubber aggregate, while the addition of hybrid fibers improves the mechanical properties despite the negative effect on the rheological properties of rubberized SCC. The tensile strengths increased significantly by the inclusion of 0.35% hybrid fibers. The positive action of the two types of fibers led to this increase. The combination of rubber aggregate and the hybrid fibers in SCC could affect its mechanical properties positively by balancing the weakness in strength due to the lack in of bonding between rubber aggregate and cement paste and to avoid the severe deterioration in tensile strength, improve the ductility, and enhance the energy absorption capacity, especially for members subjected to earthquake effects.

The Influence of Manganese Slag on the Properties of Ultra-High-Performance Concrete.

Manganese slag (MS) is a kind of chemical waste, which may pollute the environment if conventional handling methods (stacking and landfill) are applied. Ultra-high-performance concrete (UHPC)-with considerably high compactness and strength-can be used not only as a special concrete material, but also to solidify the toxic substances in solid waste. This study proposes the addition of MS to UHPC, where the mass ratio of MS varies from 0% to 40% in the total mass of MS and silica fume. The effects of MS on the fluidity, plastic viscosity, and yield shear stress are investigated, and the flexural strength, compressive strength, and dry shrinkage rate of UHPC with MS are measured. X-ray diffraction (XRD) spectrum and energy spectrum analysis (EDS) diagrams are obtained to analyze the performance mechanism of the UHPC. A rheological study confirms that the slump flow increases with the increasing rate of 0-14.3%, while the yield shear stress and plastic viscosity decrease with the rates of 0-29.6% and 0-22.2%, respectively. The initial setting time increases with the mass ratio of MS by 0-14.3%, and MS has a positive effect on the flexural and compressive strengths of UHPC. In the early curing stage (less than 14 days), the increasing rate in the specimens increases with the curing age; meanwhile, when the curing age reaches 14 days or higher, the increasing rate decreases with increasing curing age. The compactness of UHPC is increased by adding MS. Furthermore, MS can increase the elements of Al and decrease crystals of Ca(OH)2 and calcium silicate hydrate in UHPC.

Numerical modeling of the funnel multiphysical flow of fresh self-compacting concrete considering proportionate heterogeneity of aggregates

Filling ability is one of the prominent rheological properties of the self-compacting concrete (SCC), which has been studied in this research work deploying the functional behavior of the concrete through the studied funnel apparatus using the coupled ANSYS-SPH interface. Seven (7) model cases were studied and optimized. The aim of this numerical study is to propose a more sustainable mix of coarse and fine aggregates proportion that allows for most minimum flow time to enhance a more efficient filling of forms during concreting. The maximum size of the coarse aggregates considered is 20 mm and that of the fine aggregates is below 4 mm. The Bingham model properties for the multiphysics (SPH)-ANSYS models’ simulation are; viscosity = 20 ≤ μ ≤ 100 and the yield stress = 50 ≤τ0≤200\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\le {\ au }_{0}\\le 200$$\\end{document}, standard flow time, t (s) ranges; 6 ≤ t ≤ 25 and the funnel volume is 12 L. The minimum boundary flow time, which represents the time it takes for the SCC to completely flow through a specified distance, typically measured in seconds was modeled for in the seven (7) model cases. The second case with 40% coarse mixed with 60% fine completely flowed out in 16 s, thus fulfilling the minimum flow time. This minimum flow time was considered alongside other relevant parameters and tests, such as slump flow, passing ability, segregation resistance, and rheological properties (stresses), to comprehensively assess the filling ability of SCC in this model. By considering these factors and the optimized mix (40%C + 60%F:16s), engineers and researchers can optimize the SCC mix design to achieve the desired flowability and filling performance for their specific construction applications. The multiphase optimized mix was further simulated using the coupled interface of the ANSYS-SPH platform operating with the CFX command at air temperature of 25 °C. The results show energy reduction jump at the optimized flow time. Ideally, the mix, 40%C + 60%F:16s has been proposed as the mix with the most efficient flow to achieve the filling ability for sustainable structural concrete construction.

Evaluating deterioration of the properties of lightweight foamed concrete at elevated temperatures

This paper presents the results of an experimental study of varied properties of lightweight foamed concrete (LFC) at high temperatures. The key objective of this experimental study is to investigate the thermal, rheological, physical, and mechanical properties of LFC after being exposed to high temperatures up to 800 °C. To achieve that goal, an extensive study has been carried out to obtain 10 properties, i.e., slump flow, the colour of the surface, mass loss, porosity, thermal conductivity, compressive, split tensile, and flexural strength, modulus of elasticity, and wave velocity tests. In addition, the scanning electron microscopy (SEM) test provides the compositional details of materials. All mixes with varied densities were investigated after exposure to 20, 100, 150, 200, 400, 600, and 800 °C predetermined temperatures. Results also showed that mixes have different behaviours after being exposed to elevated temperatures, yet these behaviours, mass losses in particular, can be generally categorized into three phases based on temperature levels, i.e., 20–200 °C, 200–400 °C, and 400–800 °C. According to the SEM images, it is clear that the pore distributions and void sizes were significantly affected by the density value and the level of high temperature. As the temperature elevated, the void sizes also increased, and in some cases, groups of pores combined to form giant pores. However, by increasing the density, the pores' number, size, and distribution are less influenced by increasing temperature.