Sulphonated Naphthalene Formaldehyde Research Articles

Characterization, impact and wear properties of treated and as-received graphene nanosheets reinforcement in epoxy resin composites

PurposeThis study aims to explore the enhancement of mechanical properties in epoxy resin composites through the incorporation of graphene nanoparticles, focusing on their impact and wear resistance. It investigates the role of graphene, both treated and untreated, as a reinforcing agent in composites, highlighting the significance of nanoparticle dispersion and surfactant treatment in optimizing mechanical performance.Design/methodology/approachEmploying a novel dispersion technique using a drawing brush, this research contrasts with traditional methods by examining the effects of graphene nanoparticle concentrations treated with surfactants – Polyvinylpyrrolidone (PVP) and Sulphonated Naphthalene Formaldehyde (SNF) – on the mechanical properties of epoxy resin composites. The methodology includes conducting a series of impact and wear tests to assess the influence of graphene reinforcement on the composites' performance.FindingsThe findings reveal a marked enhancement in the composites impact resistance and energy absorption capabilities, which escalate with an increase in graphene content. Additionally, the study demonstrates a significant improvement in wear resistance, attributed to the superior mechanical properties, robust interface adhesion and effective dispersion of graphene. The use of surfactants for graphene treatment is identified as a crucial factor in these advancements, offering profound insights into the development of advanced composite materials for diverse industrial uses.Originality/valueThis study introduces a unique dispersion technique for graphene in epoxy composites, setting it apart from conventional methods. By focusing on the critical role of surfactant treatment in enhancing the mechanical properties of graphene-reinforced composites, it provides a novel insight into the optimization of impact and wear resistance.

Unveiling the combined influence of higher molecular weight polyethylene glycol and superplasticizer chemistry on fresh, mechanical, and microstructural performance of internally cured mortar

The limitations of conventional water curing in tall structures and arid regions necessitate alternative hydration strategies. Use of internal curing agents in high strength concrete can effectively mitigate evaporation and promote enhanced cement hydration in the concrete. However, because the superplasticizer is a required component in high strength concrete, compatibility of the internal curing agent with superplasticizer needs to be investigated. This study investigates the efficacy of internal curing (IC) using polyethylene glycols (PEGs)–PEG 4000 and PEG 6000, in conjunction with superplasticizer from two different families, polycarboxylate ether (PCE) and sulphonated naphthalene formaldehyde (SNF) in mortar mixes. A total of ten mixes were prepared for which samples from each mix were exposed to standard water curing, room curing, and internal curing. The research outcomes reveal a novel application of PEG 6000 and PEG 4000 in conjunction with PCE-based superplasticizers at optimized dosages, presenting a promising avenue for direct implementation in mortar mixes to meet both mechanical and durability prerequisites. Optimized IC mortar mixes displayed comparable or superior mechanical and durability performance to conventionally cured counterparts. This study demonstrates the potential of PEG 6000-PCE combinations as IC agents for improved fresh and hardened properties, offering a viable alternative for challenging construction environments. Further research is warranted to explore the long-term performance and economic feasibility of IC mortars in large-scale projects.

Effect of sulphonated naphthalene formaldehyde superplasticizer on the mechanical and durability properties of concrete produced using locally sourced fine aggregate from Ghana

The use of superplasticizers is very uncommon in many developing countries. However, its inclusion in concrete enhances concrete's mechanical and durability properties. There is a yawning gap in the literature on the performance of Sulphonated Naphthalene Formaldehyde (SNF) superplasticizers in concrete, especially in the sub-Saharan construction industry where the quality of aggregates used in production is questionable. This study produced two batches of concrete produced with locally sourced pit sand, with characteristic strength of 30 MPa. One batch was without the SNF superplasticizer to serve as a control, whereas the other batch was made with the incorporation of the superplasticizer. The fresh properties of slump and air content and the hardened properties of compressive and flexural strength, elastic, and dynamic moduli were investigated. Further, durability indicators comprising sorption, water absorption, sorptivity, chloride penetration, electrical surface resistivity, and acid attack were investigated. The results of the study demonstrated that the incorporation of SNF superplasticizers in concrete resulted in improved workability and a reduction in ion mobility within the concrete. This was attributed to a decrease in the presence of interconnected pores, leading to notable enhancements in mechanical properties such as increased strength, as well as improvements in both elastic and dynamic moduli. Moreover, concrete containing SNF superplasticizer protects the concrete much better from acid attack than those without SNF superplasticizer. The study recommends the use of SNF superplasticizers in concrete for improved workability, reduced ion movement via fewer interconnected pores, and enhanced mechanical properties, potentially boosting overall durability.

Studies on Properties of Sisal Fiber Reinforced Self Compacting Concrete

Abstract: To evaluate the mechanical properties of self-compacting concrete (M30) with sisal fibers. Self-compacting concrete (SCC) mixes are produced by replacing the cement with Fly ash and with addition of sisal fiber of 0, 0.5%, 1% and 1.5% and length of fibers considered are 5mm, 10mm, and 20mm to the SCC concrete. Sulphonated naphthalene Formaldehyde condensates-based SP is used as water reducing agent. Compressive strength of SCC mix has to be determined at 7, 14 and 28 days. Flexural strength of SCC mix has to be determined at 14 and 28 days. Impact strength of SCC mix has to be determined at 28 days.

Rheological characterization of limestone calcined clay cement pastes with various generations of superplasticizers for pumping applications

The present study investigates the effect of commercially available superplasticizers (SP) of various generations, such as lignosulphonate, Sulphonated Naphthalene Formaldehyde (SNF) and Polycarboxylate Ether (PCE), on the fresh properties of Limestone Calcined Clay Cement (LC3) pastes which simulates the lubrication layer formed during the pumping of concrete. LC3 cementitious pastes with different w/b (0.25–0.55), corresponding to various concrete strength grades adopted in the construction industry, were investigated. The study involves superplasticizer optimization and rheological assessment of cementitious pastes. The findings highlight the efficacy of different generations of superplasticizers, the transient flow behaviour at varied shear rates and the solid volume fractions on the rheological behaviour of LC3 pastes. The research findings indicate that LC3 based mixtures, at optimized SP dosages with increased shear rates exhibit a notable transition in behaviour from shear thinning to shear thickening (crucial for controlling the discharge of concrete during pumping). Moreover, the study reveals that LC3 pastes containing lignosulphonate based SP demonstrate superior performance at lower solid volume fractions. On the other hand, PCE based SP combinations exhibit enhanced effectiveness at higher solid volume fractions. This research outcome helps with the rational selection of superplasticizers and its dosage for LC3 mixtures in high-shear applications, particularly for the purpose of mitigating shear thickening during pumping operations.

A Neural Network-Based Prediction of Superplasticizers Effect on the Workability and Compressive Characteristics of Portland Pozzolana Cement-Based Mortars

Portland Pozzolana Cement (PPC) mortars are predominantly employed in plastering works to achieve better workability, superior surface finish, and higher fineness to offer better cohesion with fine aggregates than the ordinary Portland cement (OPC) mortars. To achieve high performance in the cement mortar similar to cement concrete, the addition of a superplasticizer is recommended. The present study investigates the impact of addition of sulphonated naphthalene formaldehyde- (SNF)-based (0.5%, 0.6%, 0.7%, and 0.8%) and lignosulphate- (LS)-based (0.2%, 0.3%, 0.4%, and 0.5%) superplasticizers on the workability and compressive strength characteristics of PPC mortars. Plastering mortars of ratio 1 : 4 were prepared with natural sand and manufacturing sand (M sand) as fine aggregates. A flow table test was conducted on all the mortar mix proportions, and the effects of the inclusion of superplasticizers on flow properties were recorded at different time intervals (0, 30, 60, 90, and 120 minutes). PPC mortar cubes were prepared, cured, and examined to assess the inclusion of chemical admixtures on compressive strength at different ages (1, 3, 7, 14, and 28 days). The experimental findings from the workability and compressive strength of PPC mortars were analyzed, and the corresponding results were predicted using artificial intelligence. Experimental investigations demonstrated that the desired flow characteristics and higher compressive strength results were achieved from a 0.7% dosage of ligno-based superplasticizer. The predicted workability and compressive strength results at various ages acquired by implementing an Artificial Neural Network (ANN) were found to be in close agreement with the experimental results.

Strength and Workability of Concrete with Inclusion of Fly Ash, Quarry Dust and a Generic Naphthalene-based Super Plasticizer

Poor strength and workability often result in low quality concrete that can cause structural failures. This research work was conducted to improve the strength and workability of concrete at reduced amount of water due to the addition of super plasticizer by replacing partially the concrete materials: cement, with fly ash at 0%, 5%, 10% and 15%; fine aggregate, with quarry dust at 0% and 15%; and the addition of sulphonated Naphthalene Formaldehyde Condensate (SNFC) super plasticizer at 0% and 0.6% by weight of cement content reducing the amount of water to 0.45 w/c from the conventional 0.6 and 0.55 w/c ratio. Concrete cube specimens were prepared with these inclusions using grade M20 concrete and nominal mix proportion of 1:2:4. Sieve analysis test, specific gravity test, fineness test were carried out on the concrete materials, workability test was carried out on each concrete specimen, a compressive strength test and weight density test was done at 7days and 28days curing. The compressive strength of concrete made with fly ash, quarry dust and SNFC at 28days ranges from 19.58N/mm2 to 30.23N/mm2. These results were higher compared to those of conventional concrete. A combination of fly ash, quarry dust and SNFC was then recommended for solving problems of low-strength concrete.

Effect of elevated temperature on Portland Pozzolona cement based concrete using Sulphonated naphthalene formaldehyde and Polycarboxylic ether as superplasticizer

The most extensively used structural material in the world for construction purposes is concrete. It has been observed that mineral admixtures like fly ash, rice husk ash, etc., when used in concrete improves its performance at high temperatures, but the role of chemical admixtures at such high temperatures has yet not been investigated. In the current study, experimental research was done to study the role of Sulphonated Naphthalene Formaldehyde (SNF) and Polycarboxylic Ether (PCE) based superplasticizers in concrete at elevated temperatures. Concrete mixes of grade M20, M25, M30, M35 and M40 were prepared with and without superplasticizers. The concrete cube mould samples were heated at elevated temperatures of 100 °C and 200 °C for 1 h and then removed from the oven and cooled to room temperature and further tested for compressive strength. It was observed that lower grade concrete performed better than higher grade at elevated temperatures and for each grade, the mix containing SNF showed an inferior response as compared to the other two mixes at 200 °C. It was also concluded that the PCE based superplasticizer increases the compressive strength at elevated temperatures as well as at room temperature for all grades of concrete. This study also focuses on checking the durability for different grades of concrete with and without superplasticizer via water absorption test. It was concluded that percentage water absorption decreases with increase in grade of concrete owing to higher cement content, and there was no effect of SNF and PCE based superplasticizers on durability of concrete.

Flexural Strength Models for Normal Laterised and High Strength Laterised Concretes at Optimum Mix Proportions

This study develops mathematical models for obtaining optimum flexural strengths of normal laterised(NLC) and high strength laterised concretes (HSLC). The models can be expressly used to evaluate the indirect tensile strengths of both types of concretes without going through the traditional methods of mix design. Optimum mixing ratios and optimum flexural strengths predicted are also supplied by the models. The three point load method was adopted for testing for the flexural strengths. Laterite, has been widely used to partially or wholly replace sand in concrete with resultant low strengths. The production of HSLC using superplasticiser was achieved in this study. Scheffe’s simplex theory based on (5, 2) simplex lattice (for NLC) and (6, 2) simplex lattice (for HSLC) was used to optimize the mix proportions for the flexural strengths of each respective laterised concrete. Conplast SP 430 superplasticiser (a sulphonated naphthalene formaldehyde admixture) was used to obtain the high strength laterised concrete. Mathematical models were developed for the mix proportioning of the laterised concretes and all strengths predicted by the models agreed with their corresponding experimentally observed values. Using the model, the optimum flexural strength and the corresponding mix proportions for the targeted strength of laterised concrete could be easily evaluated with the help of the written Q-BASIC computer programme.

Studies on Properties of Sisal Fiber Reinforced Self Compacting Concrete

Abstract: To evaluate the mechanical properties of self compacting concrete (M30) with sisal fibers.Self-compacting concrete (SCC) mixes are produced by replacing the cement with Fly ash and with addition of sisal fiber of 0, 0.5%, 1%, 1% and1.5% and length of fibers considered are 5mm, 10mm, and 20mm to the SCC concrete. Sulphonated naphthalene Formaldehyde condensates based SP is used as water reducing agent. Compressive strength and Flexural strength of SCC mix has to be determined at 14 and 28 days. Impact strength of SCC mix has to be determined at 28 days.

Synthesis of a novel amphoteric copolymer and its application as a dispersant for coal water slurry preparation.

In this work, a novel amphoteric copolymer named Poly(sodium p-styrenesulfonate–co-acrylic acid-co-diallyldimethylammonium chloride) (P(SS-co-AA-co-DMDAAC)) was synthesized via free radical polymerization. Afterwards, P(SS-co-AA-co-DMDAAC) was explored for use as a dispersant in coal water slurry (CWS) preparation. The structure of P(SS-co-AA-co-DMDAAC) was verified by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The synthetic conditions were optimized as the feed ratio of AA to SS was 1 : 1 (for Yulin coal) or 1.5 : 1 (for Yili coal), and DMDAAC dosage was 4.0 wt% (for Yulin coal) and 6.0 wt% (for Yili coal) toward total monomers. The performances of P(SS-co-AA-co-DMDAAC) as a dispersant for CWS were evaluated by various technologies, such as apparent viscosity, zeta potential, static stability and contact angle measurements. The results revealed that the optimized dosage of P(SS-co-AA-co-DMDAAC) in CWS preparation was 0.3 and 0.4 wt% for Yulin coal and Yili coal respectively. In this optimum condition, CWS prepared using P(SS-co-AA-co-DMDAAC) as dispersant showed a typical shear thinning behaviour and excellent stability, which are desired in industries. The rheological models also confirmed the pseudo-plastic characteristics of CWS. Finally, compared with the widely used anionic dispersant naphthalene sulphonate formaldehyde condensate (NSF) and poly(sodium p-styrenesulfonate) (PSS), P(SS-co-AA-co-DMDAAC) developed in this work exhibited better slurry making performance. The introduction of cationic functional groups promoted the adsorption of the dispersant, which further enhanced the electrostatic repulsion and steric hindrance among coal particles. Accordingly, the viscosity of CWS decreased and static stability enhanced.

A study on the setting and flow behaviour of alkali activated slag/fly ash composites in ambient condition

Alkali-activated binders (AAB) are considered as a promising sustainable future construction material, and promoted as an environmentally beneficial option when compared to Ordinary Portland Cement (OPC). Portland cement-based concrete is the most used material in the construction industry. In the production of OPC, harmful gasses like CO2, NO2, SO2 and specks of dust are discharged into the atmosphere due to calcination of limestone and combustion of fossil fuel. Hence in the present scenario, it has become an emphatic necessity to replace Ordinary Portland Cement based concrete with AAB based system (geopolymer) which is more sustainable. The characteristics of geopolymer composites are predominantly influenced by some of the variables such as temperature and time of curing, alkaline solution to solid binder ratio, water content, type of alkaline activators used, molarity of alkaline solution, chemical composition of aluminosilicate precursors etc. Although geopolymer systems are good in terms of durability and strength, the main issue faced for its less popularity in the field application is its low workability, poor slump retention and too fast setting.The aim of this experimental study is to investigate the compatibility between modern generation superplasticizers (SP) and various alkali activated binder systems prepared using industrial wastes and the evaluation on the effect of alkali binder ratio (a/b) on the fresh properties of alkali activated binder (AAB) systems. Considering the practical implications, it is the need of the hour to develop a geopolymer mix setting in ambient condition. This study focuses on setting and flow behaviour of the alkaline activated composites of slag and fly ash in ambient condition only. The slag/fly ash ratios of 100/0, 75/25, 50/50 and 25/75by mass and alkali-to-binder ratios of 0.4 to 1 with an increment of 0.1 were used for the study. The type of superplasticizer used for the study is Sulphonated Naphthalene Formaldehyde (SNF) with dosages of 0%, 1%, 2% and 3%. The setting time and the flow of the paste were determined using vicat apparatus and mini slump cone respectively. The penetration resistance of the setting paste was also measured using vicat apparatus. The test results revealed that even though the setting time increase marginally with SP dosage, the use of SNF was not much effective in prolonging the setting time of alkali activated pastes. There was tremendous increase in the initial and final setting time for pastes with an increase in a/b ratio.

Effects of slag and superplasticizers on alkali activated geopolymer paste

Geopolymers are a type of amorphous alumino-silicate product, and can be synthesised by the polycondensation reaction of geopolymeric precursor and alkali polysilicates. The binder is prepared by the alkaline activation of industrial by-product materials like fly ash, slag, metakaolin, rice husk ash, etc. as a source for aluminosilicate. The most commonly used alkaline activator is the combination of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). Chemical admixtures are indispensable in alkali activated systems owing to its poor fresh properties such as workability, too quick setting etc. In this study, the chemical admixture – alkali activated binder interactions were carried out by using latest generation superplasticizers, such as Polycarboxylic ether admixture (PCE) and Sulphonated naphthalene formaldehyde (SNF). Mini slump test, initial and final setting time tests were conducted in alkali activated slag blended fly ash based geopolymer paste and the test results were analyzed with respect to parameters such as alkali to binder ratio (a/b), proportion of slag in blended geopolymer paste, type and dosage of superplasticizers. The test results indicated that the workability and setting time of alkali activated geopolymer paste enhanced due to the increase in alkali content and the reduction in slag content. Based on the effect of chemical admixtures in geopolymer mix, SNF performed better than PCE admixture with regards to mini slump test for all the mixes; whereas in the case of setting time test, SNF showed better results only for the mix with 100% slag. In the case of slag blended fly ash based geopolymer paste, both PCE and SNF showed similar effects, and also it was observed that, the flow of the paste got enhanced when the dosage of superplasticizers is increased from 0 to 3% by weight of binders.

Effect of superplastizicer type on the fresh and strength properties of alkali activated slag composites

Nowadays, the demand for green concrete has increased due to the greenhouse gas emissions and uncontrolled pollution from the cement industry. At the same time, the green concrete should exhibit better mechanical properties and durability characteristics when replacing conventional concrete without compromising on the fresh properties. A better solution for the production of green concrete is to use air cured Alkali Activated Slag (AAS) composites, an innovative and sustainable binding material with very low carbon footprint. However, AAS exhibits demerits such as quick setting and poor workability and this demands the use of superplasticizers in such binder systems which are less explored thus far. Hence, this paper presents a study on the influence of superplasticizer type on the fresh and strength properties of AAS mortar. Paste/mortars were prepared with alkali activators composed of sodium silicate and sodium hydroxide and tested to study the setting times, workability, and evolution of compressive strength. It is found that the fresh properties are improved by increasing the alkali to binder ratio and the dosage of superplasticizer. Both sulphonated naphthalene formaldehyde (SNF) and polycarboxylate ether (PCE) based admixtures were found to be effective in alleviating the negatives of air cured alkali activated paste/mortar systems.

A study on compatibility of superplasticizers with high strength blended cement paste

Adoption of High-Performance Concrete (HPC) made with low water to binder ratios in practical applications are being encouraged widely for enhanced development of high early strength and durability. The type of superplasticizers incorporated, highly influences the development of HPC. At low water-cement ratio, HPC is made workable by the incorporation of superplasticizers. The wrong proportion of cement and admixture in a mix causes low fluidity, rapid/delayed setting, segregation, bleeding etc. Therefore, it is important to underline the interaction mechanism between cement and superplasticizer for the better utilization of concrete. As more blended cements are used now a day, it is imperative to investigate the compatibility of superplasticizers in such paste systems. In this study, the saturation dosages and compatibility of sulphonated naphthalene formaldehyde (SNF) and poly carboxylate ether (PCE) superplasticizers with cement paste prepared from Ordinary Portland Cement (OPC) 53 grade, Portland Pozzolana Cement (PPC) and Slag cement (PSC) for different water-binder (w/b) ratios are analysed using the marsh cone test and mini slump test. As per the result obtained, PSC was found to have higher saturation dosages than OPC and PPC. The optimum dosages for PCE admixture are lower than that for SNF as their mechanism of action are different.

Hardened Properties of Concrete Containing Copper Slag, Rock Dust and Polypropylene Fiber

The concrete is the material that is obtained from concrete forming materials. These raw materials are mixed in particular proportions, these proportions are based on different concrete grades. These concrete grades defines the strength of the concrete. Construction of structures are based upon concrete, the construction process is growing day by day at a huge scale, hence there is more demand for the raw materials. In order to maintain the demand, excessive extractions of raw materials are done, which makes environment more harmful. In order to limit the extraction of natural raw materials that are used for producing concrete mix, alternative supplementary materials are replaced with fine aggregates. This study involves using of alternative supplementary materials as partial replacement of fine aggregate by copper slag and rock dust, copper slag and rock dust are used at various proportions. The various proportions of rock dust and copper slag are 0% to 50% replacement at an increment of 5% interval. Polypropylene fiber is the material that is added as supplementary material to the concrete mix, it is added at constant volume of 1.5% volume of concrete, it is mixed in concrete to improve toughness and reduce shrinkage of concrete. Super plasticizer admixture that is used is Conplast SP430DIS which contains sulphonated naphthalene formaldehyde is added to cement based on site trails which increases the early concrete strength. Combining copper slag, rock dust, polypropylene fiber and super plasticizer admixture in modified concrete gave best results when compared to conventional concrete due to content of silica in copper slag. Hence this combination can be used for further investigation.

Incremental effect of saccharum officinarum addition on strength characteristics of geopolymer composite specimens

This paper reports the development of geopolymer concrete by adopting saccharum officinarum molasses and naphthalene sulphonate formaldehyde as admixtures. The behavioural effect of these admixtures on geopolymer is investigated. In the first stage, geopolymer concrete based on ordinary fly ash was prepared. In the second stage, by varying the percentages of cement (0 to 8%) with equal percentages of admixtures, three more geopolymer concrete mixes were prepared. Fresh and hardened properties of geopolymer concrete specimens were obtained by performing different tests. In addition, the concrete specimens were tested for ultrasonic pulse velocity, drying shrinkage and standard consistency. The findings of this study concluded that: the incremental addition of saccharum officinarum molasses improved the workability, boosted the durability and also enhanced the strength of geopolymer concrete. Further with the addition of cement in the range of 4 to 8% at a constant admixture content of 1.2%, strength and durability of geo-polymer concrete improved.

Coupled effect of superplasticizer dosage and fly ash content on strength and durability of concrete

The incorporation of fly ash in concrete enhanced the durability of portland cement concrete more effectively. Fly ash is incorporated as a mineral admixture because of its advantageous properties like pozzolanic reaction and pore refinement. At the point when fly ash is added in concrete, calcium hydroxide, liberated during cement hydration, reacts with the reactive silica present in fly ash and forms calcium silicate hydrate(C-S-H) gel. This research investigates the influence of fly ash in conjunction with four different superplasticizers (SP) namely Polycarboxylate ether (PCE), Lignosulphonate (LS), Sulphonated Melamine Formaldehyde (SMF) and Sulphonated Naphthalene Formaldehyde (SNF) and on the mechanical and durability properties of concrete. Concrete was made with different levels of class F flyash replacement (0,15, 25, and 35% by mass) of cement, the w/c ratio were maintained constant as 0.37 and the superplasticizer dosage corresponding to saturation dosage. The saturation dosage of superplasticizer is measured by conducting marsh cone and minislump tests. The mechanical and durability properties tested were compressive strength, splitting tensile strength and Sorptivity. PCE based superplasticizers are found to be more effective. Modification in the mechanical by increase in later age strength and durability properties by increase of the concrete was observed with the addition of fly ash and superplasticizer in control mix

Microstructural and rate of water absorption study on fly-ash incorporated cement mortar

Today durability is the most concerning factor in the construction field. Durability and strength are mainly controlled by microstructure of the concrete. Dense microstructure with less interconnected pores results in good strength and durable concrete. A dense microstructure can be obtained by providing good compaction, curing and by the use of mineral admixtures. This paper deals with the study on the effect of fly ash addition and superplasticizer dosage and its family in improving the strength, microstructure and durability of mortar. For this purpose mortar is prepared at a water to cement ratio of 0.37 with ordinary portland cement, class F fly ash at different percentage replacement to cement such as 0%, 15%, 25%, and 35% and superplasticizer. The superplasticzer from four different family such as Polycarboxylate ether (PCE), Lignosulphonate (LS), Sulphonated Naphthalene Formaldehyde (SNF) and Sulphonated Melamine Formaldehyde (SMF) is also used in this study. Durability of the mortar is determined by checking the 28th day rate of water absorption in mortar specimen and also by checking the size and connectivity of the pores by means of microscopic study in hardened concrete. There is decrease in 28th day compressive strength for mortar specimen with all levels of fly-ash replacement was observed in this study. Improvement in the compressive strength of the mortar compared to control specimen were observed with the addition of superplasticizer in all levels of addition of fly-ash. A good correlation between the pore size and compressive strength were also observed in this study

Influence of Aggregate Size on Self Compacting Concrete using Nafores 801 Liquid as Plasticizer

Self-Compacting Concrete (SCC) is highly useful in congested reinforced structures where vibration or compaction prove difficult. It's a concrete that can flow, consolidate under its own weight and completely fill the formwork without further vibration. In this research, laboratory investigation of SCC mix prepared from three different recipe set of aggregates (20mm, 12.5mm, and 10mm) down size and mix designed for 1: 1 1 /2: 3 mixing proportion with w/b ratio of 0.56 and Sulphonated Naphthalene Formaldehyde dosage (1.2% by weight of cement) was affirmed based on field trial. The SNF acting as Super plasticizer (Water Reducing Agent) and influence of the admixture was examined via the workability tests. However, it was examined by using the slump flow test, V - flow, and L - box test. The designed mix achieved consistency and self compatibility under its own weight without any external vibration or compaction. 150mm x150mm x 150mm cube specimen cast was done and thereafter cured for twenty eight (28) days. The strength development for each of the specimen at 3, 7, and 28 days for the respective mix was examined and the results showed that increase in the compressive strength with respect to the curing age, enhancement in workability, reduction in shrinkage, and bleeding of the concrete mix of SCC holds to the inclusion of Super Plasticizer in the mix. The significance of this research work lies in its attempt to provide information on the performance of Self Compacting Concrete made from different recipe sets of aggregate and its major advantage in salvaging time and labour. Keywords: Aggregate, Curing, Self-Compacting Concrete (SCC), Sulphonated Naphthalene Formaldehyde, Plasticizer, Strength, and Workability.