J-ring Tests Research Articles

Performance Evaluation of Self-Compacting Concrete using PPC and Flyash

India, as the world's second-largest consumer of concrete, faces an urgent need for sustainable construction practices to address the environmental challenges of cement production and its eventual scarcity. This research investigates the effect of fly ash (FA) as a partial replacement for cement in self-compacting concrete (SCC) across various grades (M30, M50, M70), focusing on both fresh and hardened properties. The study explores the impact of fly ash content (ranging from 0% to 50%) on workability, compressive strength, split tensile strength, and flexural strength. Fresh properties were evaluated through slump flow, V-funnel, L-box, and J-ring tests, demonstrating that fly ash enhances flowability, passing ability, and filling ability up to 30% replacement. However, higher FA content negatively impacted the fresh properties, particularly in lower-grade mixes. In terms of hardened properties, compressive, split tensile, and flexural strengths improved up to 20-30% fly ash, attributed to its pozzolanic reaction and better particle packing. Beyond these levels, strength reduced due to increased paste viscosity and cement dilution. Overall, the research emphasizes the need for optimal fly ash content to maximize strength, workability, and durability in SCC applications

Effect of Sporosarcina Pasteurii on Rheological and Strength Properties of Bio-Self Compacting Concrete

The study was conducted to evaluate the rheological and strength properties of bio-self compacting concrete. The materials used are cement, fine and coarse aggregates, bacteria (Sporosarcina pasteurii), and superplasticizer. Preliminary tests were conducted on the materials to ascertain its conformity to standard, and a full factorial design of experiment was adopted. The bacteria nutrient was varied at a ratio 1:3 of the bacteria content (i.e. 75% nutrient and 25% bacteria) at 10^5 cell/ml Sporosarcina pasteurii which was added to the fresh concrete at 5-25ml dosage by weight of water at 5ml increment, while the superplasticizer was added into the fresh concrete at 0.2-1.0% at 0.2 % increment by weight of cement which translated to 234 concrete samples. The rheological tests conducted were slump, V-funnel, L-box, and J-ring test, while the concrete strength tests conducted were compressive, flexural, and split tensile strength. Results from the experiment showed that workability of most of the bio-self compacting concrete is very high compared to the control concrete, and are within the range specified by codes, and the 28 days compressive strength of concrete produced by adding 20 – 25 % bacteria and 0.4-0.8% superplasticizer had 28 days compressive strength equal or greater than the control concrete. Also, the 28 days flexural strength of control concrete is significantly higher than flexural strength of all the bio self-compacting concrete, while the split tensile strength of bio self-compacting concrete produced by adding 25% bacteria and 0.4 – 0.8% superplasticizer is higher than the control concrete.

Effects of Volcanic Tuff Use on the Rheological and Mechanical Properties of Self-Compacting Concrete

The rise in demand of concrete products has led to overexploitation of river sand the main fine aggregate in concrete resulting in major environmental degradation. As a result, researchers have focused their efforts on developing eco-friendly concrete using alternative renewable materials like volcanic tuff and other natural pozzolana types. This study therefore, aims at investigating the use of Kenyan, Kitengela volcanic tuff as a partial replacement of river sand in self-compacting concrete, and determining the effects it will have on the rheological and mechanical properties of the self-compacting concrete. The study involved partially replacing river sand with volcanic tuff in percentages of 0%, 2.5%, 5%, 7.5% and 10% and carrying out rheological tests (V-funnel test, L-box test, T-500 test and J-ring test) on fresh concrete and mechanical tests (compressive strength and tensile strength tests) on hardened self-compacting concrete on days 7, 14, and 28 to determine the effects of volcanic tuff on properties of both fresh and hardened self-compacting concrete. There was a general decrease in rheological properties (flow and passing abilities) of self-compacting concrete with increase in volcanic tuff percentage replacement from 0 % to 10%, with least flow and passing abilities recorded at 10% replacement. Similarly, increase in volcanic tuff percentage replacement led to decrease in both compressive and tensile strength of self-compacting concrete with lowest values recorded at 10% volcanic tuff replacement.

Physical and mechanical properties of self-compacting geopolymer concrete with waste glass as partial replacement of fine aggregate

A significant amount of waste glass is generated every year. Waste glass particles as replacement of fine or coarse aggregates in concrete is recently attracting attention in the construction industry. While several studies reported how the physical and mechanical properties of concrete are affected due to the use of waste glass particles in concrete, studies related to geopolymer concrete containing waste glass particles are limited. This present study investigates the effect of the gradation of waste glass particles in geopolymer concrete. Waste glass particles are used as fine aggregate, and two different gradations are considered – well graded fines and coarse graded fines. In order to determine the optimum amount of sand replacement, three different percentages (10 %, 30 %, 50 % of total fine aggregate) of well-graded and coarse graded fine waste glass particles are considered. In addition, for limited mixes, chopped basalt fibre was incorporated in the mix. The proposed mix design is for self-compacting geopolymer concrete, and therefore, the workability properties of the developed mix are reported in terms of slump flow, T-500 and J-ring test. The effect of gradation and content of waste glass particles are evaluated in terms of compressive strength (28- and 56-days), modulus of elasticity, and split tensile strength. Microscopic analysis is performed to observe the distribution of waste glass particles and potential reasons for various failure modes.

Experimental Investigation on Influence of Binder Constituents on Workability, Strength and Microstructure of SCGC

Abstract: The present study investigates the influence of bacteria on varying binder constituents to enhance the workability, strength, and microstructure properties of self-consolidating geopolymer concrete (SCGC). Geopolymer concrete is a sustainable alternative to conventional cement-based concrete, as it utilizes industrial by-products and reduces carbon emissions. The bacterial strains, known for their ability to promote mineral precipitation and improve concrete properties, are introduced in varying proportions to the geopolymer binder constituents. The goal of this experimental investigation is to better understand how Bacillus Cohnii bacteria affect the workability and strength of alkali-activated Self-consolidating Concrete (SCC) mix compositions. Three mix formulations with variable binder contents in the range of 400 kg/m3 and 450 kg/m3 were the subject of experimental research. This research work aims on investigating various binder constituents on Strength, Workability and Microstructure. Three different SCGC mixes were prepared by varying the percentage fly ash and Alcofine in range of 0%, 10%, 30% and 0%, 5%, 5% to the quantity of GGBFS respectively. Alcofine increases final setting time. For all mixes, ambient curing was done. As per EFNARC recommendations, the fresh qualities of SCGC were determined using the Slump test, T50 slump test, L-Box test, V- funnel test, and J-ring test. By conducting compression tests, split tensile tests, and flexure tests after 7, 14 and 28 days, the strength characteristics of SCGC were identified. The SCGC's microstructure and chemical composition were both determined by SEM and EDS analyses, respectively. According to test results, an alkaline solution sample with a 13M concentration and 450 kg/m3 of binder produced the highest compressive, flexural, and split tensile strengths after 28 days producing values of 58.32 MPa, 3.5 MPa, and 4.27 MPa, respectively.

Effect of fibre diameter and tensile strength on the mechanical, fracture, and fibre distribution properties of eco-friendly high-strength self-compacting concrete

The development of Steel Fibre-Reinforced Self-Compacting Concrete (SFR-SCC) is a complex task with significant practical implications for the construction industry. However, the absence of established design guidelines and recommendations, and the limited availability of design methodologies, present a significant challenge. Achieving the targeted rheological and mechanical properties while simultaneously minimising production costs requires a comprehensive understanding of the optimal blend of fibre type and quantity and the coarse aggregate content. This paper addresses the impact of steel fibre properties on the rheological and fundamental mechanical properties of eco-friendly high-strength self-compacting concrete (HSSCC), using 40% ground granulated blast furnace slag (GGBS) as a cement replacement. The research focused on 30 mm long hooked-end steel fibres with tensile strengths of 1345 MPa and 3070 MPa, and diameters of 0.55 mm and 0.38 mm, respectively. In addition, the study investigated the combined effect of coarse aggregate content and steel fibre type on the performance of eco-friendly HSSCC. The fresh properties of eco-friendly HSSCC were assessed using the slump flow and J-ring tests. Furthermore, mechanical and fracture properties such as compressive strength, splitting tensile strength, elastic modulus, four-point flexural strength, and three-point flexural strength on notched prisms were also evaluated. The distribution and alignment of steel fibres in the HSSCC were assessed using image analysis techniques, which showed that the steel fibre diameters were a crucial factor in the fibre dispersion. The results demonstrated that using steel fibres with higher tensile strength and smaller diameter significantly enhanced the splitting tensile strength, flexural strength, and fracture energy, compared to steel fibres with larger diameters and lower tensile strengths. Additionally, the study indicated that the elastic modulus and fracture energy of eco-friendly HSSCC reinforced with both types of steel fibre are highly dependent on the content of coarse aggregate used. The study highlighted that the coarse aggregate proportion and the steel fibre characteristics were two vital factors that influenced the rheological and mechanical properties of HSSCC and must be considered during the mix design process to optimise the desired properties while also minimising production costs.

Properties of Self-Compacting Concrete Produced with Optimized Volumes of Calcined Clay and Rice Husk Ash-Emphasis on Rheology, Flowability Retention and Durability.

The durability of concrete requires a dense microstructure which can be achieved by using self-compacting concrete (SCC). Both calcined clay (CC) and rice husk ash (RHA) are promising supplementary cementitious materials (SCMs) that can partially replace cement, but their use in SCC is critical due to their higher water demand (WD) and specific surface area (SSA) compared to cement. The effect of partial substitution of cement at 20 vol-% with binary and ternary blends of CC and RHA on flowability retention and durability of SCC was investigated. The empirical method of SCC design was adopted considering the physical properties of both CC and RHA. The deformability of the SCC was evaluated using the slump flow and J-ring tests. The T500 time and the V-funnel test were used to assess the viscosity of the SCC. The flowability retention was monitored by the plunger method, and flow resistance was determined based on the rheological measurements of SCC. The evolution of the hydrate phases of the binder in SCC was determined by thermogravimetric analysis, while the durability was evaluated by a rapid chloride migration test. Cement partial replacement with 20 vol-% CC has no significant effect on fresh SCC, flowability retention, compressive strength and durability properties. On the other hand, 20 vol-% RHA requires a higher dosage of SP to achieve self-compactability and increase the viscosity of SCC. Its flowability retention is only up to 30 min after mixing and exhibited higher flow resistance. It consumes more calcium hydroxide (CH) and improves the compressive strength and chloride resistance of SCC. The ternary blending with CC and RHA yielded better fresh SCC properties compared to the binary blend with RHA, while an improved chloride penetration resistance could be achieved compared to the binary CC blend.

Comparative analysis of quaternary blended self-compacting concrete (QBSCC) mixes incorporating induction furnace slag (IFS) and crushed stone aggregate: A performance study

This study explores using Induction Furnace Slag (IFS) as aggregate in Quaternary Blended Self-Compacting Concrete (QBSCC) mixes. The experimental work consists of two stages. Stage I focuses on determining the optimal QBSCC mixes, aiming to develop environmentally friendly Self-Compacting Concrete (SCC) by utilizing different types and ratios of cementitious materials. A total of 27 QBSCC mixes were prepared with a reference SCC mix consisting of 100% ordinary Portland cement (OPC), are prepared considering water binder (w/b) ratio of 0.4. The quaternary blended mixes are created by combining OPC, class F Fly Ash (FA), Silica Fume (SF) and Ground Granulated Blast Furnace Slag (GGBFS). The replacement ranges for SF are set between 2.5% and 7.5% in increments of 2.5%, for FA between 10% and 20% in increments of 5%, and GGBFS between 30% and 50% in increments of 10%. In stage II, the optimized QBSCC mixes are further enhanced by incorporating IFS, the properties in the fresh state such as slump flow, V-funnel, L-box, and J-ring tests are conducted for all SCC mixes, all of which comply with the EFNARC guidelines. The mechanical characteristics studied, includes compressive strength (cube and cylinder), split tensile strength (at 3, 7, 28, and 56 days), flexural strength (at 28 and 56 days), elastic modulus, shear strength and pull-out bond strength (at 56 days) are evaluated. It is noted that the hardened properties of SCC mixes containing IFS exhibit slightly higher values compared to crushed stone aggregate SCC mixes. Furthermore, an increase in Supplementary Cementitious Material (SCM) content in QBSCC mixes leads to a decrease in the hardened properties, irrespective of the kind of aggregate used. The QBSCC mixes identified as SCC57.5/42.5, SCC52.5/47.5, and SCC47.5/52.5 are determined to be the preferred blends for producing Self-Compacting Concrete (SCC). Remarkably, Induction Furnace Slag (IFS) can be utilized as both fine and coarse aggregate, completely replacing conventional aggregates, regardless of the content of supplementary cementitious materials (SCM). This finding highlights the notable effectiveness of IFS as a replacement material in SCC production.

Effect of various powder content on the properties of sustainable self-compacting concrete

This research goal is to evaluate the characteristics of glass powder (GP), quartz powder (QP), and limestone powder (LP) as Supplementary Cementitious Materials (SCMs) to replace cement content in terms of fresh and hardened properties of Self-Compacting Concrete (SCC) for sustainable building construction. Moreover, the obtained results were modeled using a soft computing approach. This investigation created ten mixtures incorporating varying percentages of GP, QP, and LP by replacing cement at about 0 %, 10 %, 20 %, and 30 %, respectively. The slump flow and J-ring tests were done to observe how SCMs affected the properties in fresh condition. In addition, the mechanical properties and pore structure configuration of the specimens were investigated. It was observed that GP and LP positively affected the fresh properties, increasing the mixes flowability by up to 8 %. Moreover, 20 % GP was able to enhance the compressive strength by 7 % by improving the pore structure of the cement matrix, which was confirmed by the mercury intrusion porosimetry analysis. Finally, the built machine learning models indicated good accord with test outcomes for Artificial Neural Network (R2 = 0.95) and could be applied to calculate the compressive strength of concrete containing GP, QP and LP for construction housing sector.

Pull-Out behavior and microstructure characteristics of binary blended self-compacting geopolymer concrete subjected to elevated temperature

Geopolymer concrete (GPC) is an emerging green substitute for conventional cement-based concrete. Due to the eco-friendly benefits of GPC, it possesses superior strength properties. Self-compacting concrete (SCC) is a special concrete, it has the tendency to pass and fill congested areas without the help of vibrators. As the Self-compacting based Geopolymer concrete (SCGC) is a sustainable construction material, the knowledge about the thermal performance of SCGC is vital. Therefore, the current work examined the behavior of binary blended SCGC under room temperature and elevated temperatures of 821 °C, 925 °C, 986 °C, and 1029 °C. The investigation's main objectives are to examine the bond performance and microstructure of binary blended SCGC composites subjected to temperature exposure. Three types of mixes are considered in the investigation, namely FA (100% Fly Ash (FA)), F-G (50% Fly Ash (FA) and 50% Ground Granulated Blast Furnace Slag (GGBS)), and F-M (50% Fly Ash (FA) and 50% Metakaolin (MK)). The workability tests, such as the Flow test, T500 test, V-funnel test, and J-ring tests, were carried out in line with EFNARC guidelines to examine the rheological properties of SCGC. The SCGC composites were subjected to temperature exposure following ISO 834 standard fire curve. The Pull-Out (PO) test was carried out to investigate the Bond stress (BS) of the heated and unheated SCGC composites. The Bond stress of the SCGC composites decreases with an increase in temperature exposure. Test results show that the F-G mix possesses higher BS for unheated specimens, followed by F-M and FA mix. When exposed to elevated temperature, the SCGC composite mix F-G and F-M exhibit higher strength loss (%) than the FA mix. A relationship has been established between the compressive and bond stress of SCGC.

An experimental investigation of M30 grade self compacting concrete using mineral admixtures

Self-compacting concrete (SCC) is commonly used to create high-performance concrete since it does not require vibration to achieve a compacted state. The absence of standardized mix design and testing methods has hampered SCC's implementation. Since no vibration is required and noise pollution is reduced, it is gaining widespread acceptance. In construction, we have found a way to make every step of the process both less dangerous and more fruitful. This study aimed to produce a mix design for M30 grade SCC by the criteria established by EFNARC 2002. The SCC is made by substituting fly ash (FA) and metakaolin (MK) at percentages of 0%, 7.5%, 15%, 22.5%, and 30% of the cement volume and then adding 1.5 percent of superplasticizer to the resulting cement volume. According to EFNARC, the M30 grade SCC mix produced passed all of the tests above: the L-box test, the slump flow test, the V-funnel test, and the J-ring test. Additionally, compressive, tensile, and flexural strengths of 7- and 28-day-old SCC samples were tested, with results indicating that a 0%-30% substitute of MK and FA can be considered a suitable replacement and mix designs for M30 grade of metakaolin and fly ash-based self-compacting concrete have been proposed.

Performance of polypropylene reinforced self-compacting concrete

The last 10 years have seen tremendous growth in RCC, with both population growth and changes in construction methods playing a significant role. Self-compacting concrete (SCC) selection is largely influenced by the site's features, the construction's type (particularly the choice of columns and beams), and the arrangement of reinforcement. The productivity may be maximised by utilising vibrators to eliminate vibration compaction. While using SCC, concrete's performance, hardened attributes such surface quality, strength, and durability are most significantly impacted. The goal of this research is to look into the effect of Polypropylene (PF) reinforcing on the hardened concrete qualities of M30 grade SCC. In order to create mixtures with different fibre content fractions (0, 0.5, 1.0, 1.5, & 2.0 percent), a fixed amount of fly ash (25 percent) was substituted for cement by weight. The slump flow, V-Funnel, L-Box, and J-Ring tests are used to analyse fresh properties in the laboratory. Investigations are conducted on the hardened characteristics' compressive strength at 7 and 28 days, split tensile strength at 7 and 28 days, flexural strength at 7 and 28 days, resistance to acid attack at 7 and 28 days, and water absorption. Polypropylene fibres were used to achieve the highest compressive strength, which was 11.6 percent. When compared to self-compacting concrete without polypropylene fibres, the split tensile strength improved by up to 17.8 percent. The flexural strength of PF is around 15% greater, and they absorb less water.The addition of polypropylene fibres also impeded the acid attack statistics, but when we look at these results alone, we observe that all mixes acquire self-compacting characteristics utilising PFwith a fibre concentration of up to 1.0 percent. Concrete's mechanical characteristics were enhanced and its excellent endurance was shown by polypropylene fibres.

Simulating passing ability of self-compacting concrete in the J-ring test using cohesive particle liquid bridge model

Simulating passing ability of self-compacting concrete in the J-ring test using cohesive particle liquid bridge model

Pineapple fibre as an additive to self-compacting concrete

As concrete being widely used in the field of construction, the demand for the materials used is increased ­rapidly. To meet the growing demand it is necessary to use alternative materials to meet the requirements. The Pineapple leaf fibre (PALF) is a highly available material in larger quantity with lesser water content and higher fiber content which makes it as a desirable material as natural fibre. The workability characteristics of Self ­compaction Concrete (SCC) like flowability, filling ability, passing ability, resistance to segregation and bleeding of concrete were out by using slump cone, U-box, L-box, V- Funnel and J-ring test. The test result shows satisfactory results on the workability of SCC. The fresh and hardened properties of concrete were found at the ages 7 days, 14 days and 28 days for various addition of PALF and various replacements of granite powder with the fine aggregate. The addition of PALF has achieved maximum compressive strength and split tensile strength in all ages of concrete at PALF0.2. The replacement of granite powder with fine aggregate seems to be promising in achieving the maximum compressive strength and split tensile strength at the 10% of replacement.

Physical characteristics and mechanical properties of a sustainable lightweight geopolymer based self-compacting concrete with expanded clay aggregates

Geopolymer Concrete (GPC) is a unique and sustainable building material that has the potential to be transformed into a self-compacted lightweight composite for industrial applications. This paper investigates the sustainability of self-compactable lightweight geopolymer concrete (SCLGC) made from Expanded Clay Aggregate (ECA) to further explore this front. In this study, the physical properties of SCLGC, such as slump flow test, T500 test, V-funnel, and J-ring tests, are examined. Furthermore, the density, Ultrasonic Pulse Velocity (UPV), compressive strength, splitting tensile strength, and impact resistance are also tested to evaluate the mechanical properties of SCLGC mix with various concentrations of Sodium Hydroxide (SH) cured under different curing regimes. The aforenoted properties are examined following the American, Indian and European guidelines. In addition, microstructural analysis is conducted to assess the compactness and internal structure of SCLGC blends with varying SH concentrations cured under different curing regimes. Finally, the sustainability aspects of GPC and SCLGC mixes are analyzed through the Life Cycle Assessment (LCA) and Environmental Impact Assessment (EIA) to evaluate the energy requirement and CO2 emission and cost. The Sustainability analysis was performed to evaluate the energy requirement and CO2 emission of SCLGC in the production of 1 m3 concrete based on the previous literatures. The significance of the proposed research work emphasizes the utilization of ECA as an aggregate material for the development of SCLGC. The cost, carbon and energy efficiency of the SCLGC's mixes were estimated. Mix with ECA requires higher energy demand and emits high CO2 in the open atmosphere. Based on the present analysis it can be concluded that an increase in the concentration of activator solution increases the energy demand and emits more amount of CO2. The inference from the present study reveals ECA can be employed for the production of SCLGC with the replacement percentage not exceeding 50%.

Strength and Durability of Sustainable Self-Consolidating Concrete with High Levels of Supplementary Cementitious Materials.

Self-consolidating concrete (SCC) has been used extensively in the construction industry because of its advanced characteristics of a highly flowable mixture and the ability to be consolidated under its own weight. One of the main challenges is the high content of OPC used in the production process. This research focuses on developing sustainable, high-strength self-consolidating concrete (SCC) by incorporating high levels of supplementary cementitious materials. The overarching purpose of this study is to replace OPC partially by up to 71% by using fly ash, GGBS, and microsilica to produce high-strength and durable SCC. Two groups of mixtures were designed to replace OPC. The first group contained 14%, 23.4%, and 32.77% fly ash and 6.4% microsilica. The second group contained 32.77%, 46.81%, and 65.5% GGBS and 6.4% microsilica. The fresh properties were investigated using the slump, V-funnel, L-box, and J-ring tests. The hardened properties were assessed using a compressive strength test, while water permeability, water absorption, and rapid chloride penetration tests were used to evaluate the durability. The innovation of this experimental work was introducing SCC with an unconventional mixture that can achieve highly durable and high-strength concrete. The results showed the feasibility of SCC by incorporating high volumes of fly ash and GGBS without compromising compressive strength and durability.

Propriedades de concreto auto-adensável contendo cinzas volantes

Self-compacting concrete is a high performance concrete with excellent rheological properties that can be spread in areas of difficult access. Selfcompacting concrete requires a high consumption of cement production, which has a negative effect on the environmental aspect, since the production of cement releases significant amounts of CO2. This study aims analysis the influence of the substitution (20 and 40% by weight) of Portland cement by fly ash on the selfcompacting concrete properties in the fresh state (spreading, workability, passing ability - J-ring test, viscosity - V-funnel test) and hardened (compressive strength).The passing ability was proved more effective to the mixture with 20% of replacement. To the viscosity, control concrete had lower flow time in V-funnel. The compressive strength results at 28 days showed a reduction of 9.5% for concrete with 20% fly ash and 77.0% for concrete with 40% fly ash compared to the control concrete.

Assessment of the Rheological properties of Aluminum dross in self-compacting concrete

This research assessed the rheological properties of aluminium dross in self-compacting concrete. Aluminium dross, solid waste from the aluminium processing industry, was used as a partial replacement for cement in the development of eco-friendly concrete. This was done in a bid to reduce the cost of management of this waste in track with the ‘waste to wealth’ initiative. In this article, aluminium dross was used as a partial replacement for cement at 0, 4, 8, 12, 16 and 20% content. The rheological test (workability) was carried out according to European Federation for Specialist Construction Chemicals and Concrete Systems (EFNARC) specifications. To this end the slump test, L-box, V-funnel and J-ring test was carried out at the replacement. The slump flow result indicated satisfactory result up to 20% addition, which indicates the good flowability characteristics of the concrete. The result of the research showed that aluminium dross, to a large extent, influenced the workability of the concrete produced. At 10% addition of this solid waste, the rheology was unsatisfactory from L-Box and V-funnel test result. The outcome of this research will guide researchers, engineers, and concrete users on the proper timing for mixing the special eco-friendly self-compacting concrete in the construction industry.

Influence of Amount of Light Weight Aggregate on Properties of Self Compacting Concrete

Concrete with low density is termed lightweight concrete. The unit weight of such concretes is about two-thirds of normal concrete. Most structural lightweight concretes weigh between 1600 and 1760 kg/m3. Design strengths between 20 to 35 MPa are common. The lightweight nature of these concretes is usually obtained either by using lightweight cellular aggregates. LWC can be produced by using lightweight materials like Lightweight Expanded Clay Aggregate, Pumice stone, expanded shale, Perlite etc. Structural lightweight aggregate can be produced naturally or from environmental waste. use of these aggregates can reduce the density of concrete, the self-weight of the structure and it helps to construct larger precast unit. Lightweight concrete (LWC) is an exceptional solution in terms of decreasing the dead weight of the structure, while self-compacting concrete (SCC) eases the pouring and eliminates construction difficulties. Investigations are also reported the literature on the performance of micro silica in SCC wall panels. The Self-Compacting Concrete made by partially varying coarse aggregate with the lightweight pumice aggregate is described in the paper. This paper presents the fresh and hardened properties of low strength grade and standard grade, self-compacting concrete partially incorporating pumice as coarse aggregate with different replacements. This experimental study also compares the fresh and hardened concrete properties of conventional self-compacting concrete and Light weight self-compacting concrete. The fresh concrete test properties were examined using the slump flow, T500, and J-ring tests. Hardened concrete test properties incorporate 7-, 28- and 56-days compressive strength tests. From the test results it is found that Lightweight self-compacting concrete exhibits better flow property than conventional self-compacting concrete.

Investigating the Behavior of Waste Alumina Powder and Nylon Fibers for Eco-Friendly Production of Self-Compacting Concrete.

Self-compacting concrete (SCC) incorporating secondary raw materials has been extensively used around the globe due to its improved fresh, mechanical and durability properties. This study was planned to evaluate the suitability of locally available waste alumina powder (AP) and nylon textile fibers (NF) as a partial replacement for fine and coarse aggregates with the ultimate goal to locally produce SCC with desired properties. The used AP was acquired from a local market and NF was collected from a local textile factory. Various dosages of AP (10%, 20%, 30%, 40% and 50% by volume of fine aggregates) and NF (1% and 2% by volume of coarse aggregates) were studied. Tests including slump flow, V-funnel and J-ring tests were performed for examining the fresh properties of developed SCC. Results showed that the addition of AP has an insignificant effect on the superplasticizer dosage for maintaining a constant flow of 70 cm. However, a higher dosage of superplasticizer was required for a mixture with increasing dosages of NF to sustain a constant flow. Similarly, slump flow time (for a spread of 50 cm) and V-funnel time increased for mixtures with higher dosages of AP and NF. Tested SCC mixtures incorporating 40% and 50% of AP with 1% and 2% of NF showed an extreme blocking assessment due to their increased interparticle friction, the higher water absorption capacity of used AP and NF leading to increased flow resistance and hence, showed lower passing ability. The compressive strength was 16% higher for specimens incorporating 40% of AP due to the filling effect of AP which fills the micro-pores, leading to a more dense and compact internal micro-structure, confirmed through scanning electron microscopy analysis. An ultrasonic pulse velocity test conducted on hardened specimens verified the findings of the compressive strength results. Moreover, it was observed that NF has an insignificant effect on the compressive strength; however, flexural strength was increased due to the incorporation of NF, especially at higher dosages of AP.