scholarly journals A Study on Porous Sealing Efficacy of hydrophilic Admixture on Blended Cement Concrete

2018 ◽  
Vol 7 (2.12) ◽  
pp. 446
Author(s):  
L Krishnaraj ◽  
P T. Ravichandran ◽  
M V.A.Karthik ◽  
N Satheeshram Avudaiyappan ◽  
. .

The life of the concrete is strongly influenced by durability parameters. The permeability is one of the main characteristics influencing the durability of concrete. The concrete is more permeable due to the ingress of water, oxygen, chloride, sulphate, and other potential deleterious substances. The durability of concrete is mainly affected by pore structure system of concrete and addingthe supplementary cementitious materials (SCM), such as fly ash, slag cement, and silica fume can be decrease permeability. Crystalline technology enhances the strength of concrete by filling the poresand micro-cracks with non-dissolvable substances. To study the efficiency of crystalline formation in concrete in terms of more permeable should be guaranteed through a specific technique.The effectiveness of crystalline waterproofing system with partial replacement cement by GGBS is studiedin terms of strength and durability. The performance of the two different types of crystalline waterproofing integral admixtures has been studied for compressive strength, Split tensile strength, workability, water permeability, Rapid chloride permeability test and porosity in this paper.The early strength increased in GGBS with crystalline admixture concretes compare to the control concrete. No significant strength reduction is observed in GGBS concretes with crystalline admixture when replaced with 20% and 40% of cement than control concrete.  

2020 ◽  
Vol 184 ◽  
pp. 01100
Author(s):  
C Vivek Kumar ◽  
MD Aiman Parvez ◽  
T Srinivas

At Present Water is the most essential material in the modern era. In general, Curing of concrete is retaining moisture in the concrete for the period of early ages precisely within 28 days of placing concrete, to improve anticipated properties. Appropriate curing of concrete is crucial to obtain extreme durability, especially if the concrete is exposed to serve conditions where the surface will be imperiled to excessive wear, assertive solutions, and severe environmental circumstances. Poor curing practices adversely affect the desirable properties of concrete which constitutes a major influence on the permeability of a given concrete.Unpredicted shrinkage and temperature cracks be able to diminish the strength, durability and serviceability properties of the concrete. The surface zone will be critically damaged by increased permeability expected to poor curing. The improvement of shrinkage in concrete is proportionate to the rate of moisture loss in concrete. When concrete is correctly cured, water preserved in concrete would facilitate continuous hydration and enhancement of enough compressive and tensile strength to withstand contraction stresses. The incessant development of strength reduces shrinkage and initial cracks or micro-cracks. As a part of this study, SCMs like Flyash (FA), Ground Granulated furnace Slag (GGBS), Silica Fume (SF). Concrete may be a mixture of cement, aggregates and water with / without suitable admixtures with self-curing agents and various proportions, which resulted in the early strength to reduce the autogenous shrinkage and increase in durability.


2016 ◽  
Vol 857 ◽  
pp. 65-70 ◽  
Author(s):  
P. Prathebha ◽  
Santhappan Aswini ◽  
J. Revathy

The nanotechnology provides an impact on construction industry materials with new properties and produce material with better performance. This paper presents the experimental investigation on the effects of nano particles incorporated in the cementitious materials to study the strength and durability properties of cement mortar. Nano particles such as nano alumina (NA), nano ferric oxide (NF) and nano silica (NS) were mixed at different proportions of 0.5%, 1% and 1.5% by weight of binder in single and binary combinations. Mechanical properties such as compressive strength and split tensile strength; durability properties such as water absorption and rapid chloride permeability test were tested as per standards. The results showed that 1.5% of the combination of nano silica & nano ferric oxide (NSF) and nano silica & nano alumina (NSA) particles increased the mechanical strength and durability properties of cement mortar. The microstructure characteristics results revealed that the nano particles incorporated cementitious materials showed the voids were filled up with nano particles. It acts as filler in cement mortar that enhanced a dense microstructure, reduced the quantity and size of calcium hydroxide and also filled the voids of C-S-H gel structure.


Author(s):  
Leela Prasanth U ◽  
Karan Kumar H ◽  
Afzal Basha Syed

Concrete is a compound material composed of fine aggregates and coarse aggregate bonded together with fluid cement that hardens over time.The deficit of natural sand arises the need of alternative materials for replacement of natural sand. The squashed stone residue which is locally accessible modern strong waste material is ordinarily utilized as a fine aggregate in concrete. In the current examination, an exploratory program was carried out to consider the compressive and split tensile quality of concrete made utilizing stone residue as halfway substitution of fine aggregate at an increment of 10%. Zeolite is a pozzolanic material and its pozzolanic action improves the compressivestrength of concrete. Natural zeolites are supplementary cementitious materials. By adding zeolite, the investigation on the experiments will be carried out to determine the compressive strength and split tensile strength of concrete made using zeolite as partial replacement of cement up to 20 percent at an interval of 5 percent just as the way Stone dust is being replaced to achieve the objective of the project, M30 grade of concrete is prepared. The cube and cylindrical samples shall be tested after a curing period of 7 & 28 days.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1609
Author(s):  
Rohollah Rostami ◽  
Agnieszka J. Klemm ◽  
Fernando C. R. Almeida

Supplementary cementitious materials (SCMs), such as fly ash (FA) and ground granulated blast-furnace slag (GGBS), are often used as a partial replacement of cements to improve the sustainability of Portland cement-based materials and reduce their environmental impact. Superabsorbent polymers (SAPs) can be successfully used as internal curing agents in ultra-high performance cementitious materials by facilitating the hydration process and controlling the water supply in both fresh and hardened states. This paper intends to characterise the physical and chemical properties of SAPs and their sorption properties in different blended cement environments. The swelling capacity and kinetics of absorption of three superabsorbent polymers with different chemical compositions and grading were tested in different cement environments. Experimental results of their sorption performance in distinct solutions, including deionised water (DI), Portland cement (PC), and blended cements (PC-FA and PC-GGBS) and changes in pH of different solutions over time were investigated. The results showed that PC-FA solution had the lowest pH followed by PC-GGBS solution. Moreover, SAPs samples displayed the highest absorption capacities in PC-FA solutions, and the lowest swelling capacities were found in PC-GGBS solutions. Furthermore, SAP with smaller particle sizes had the greatest absorption capacity values in all solutions.


Author(s):  
Agboola Shamsudeen Abdulazeez ◽  
Amina Omolola Suleiman ◽  
Simdima Gabriel Gideon ◽  
Solomon Wutong Poki

- Presently researches all over the world is concentrating on alternative materials as partial cement replacement in concrete production. The use of pozzolanic material in concrete is becoming increasingly important because of the need for more sustainable cementing products. Volcanic ash is a form of natural pozzolan and has a chemical composition comparable to other supplementary cementitious materials. In this paper, volcanic ash was used to partially replace cement in the ratio of 0%, 5%, 10%, 15% and 20% by volume in concrete and cured in H2SO4 and MgSO4 environment. 28-day target strength was adopted and concrete tested at 7, 14, 28 and 56 days’ hydration period. Specific gravity, bulk density and setting time test on volcanic ash were carried out. Fresh concrete tests such as slump and compacting factor test were carried out along-side hardened concrete tests like compressive strength and split tensile strength. The result shows that the maximum compressive strength at 28 days was at 0% control concrete, while at 56 days the maximum strength was observed at 10% replacement of cement with volcanic ash and it is considered as optimum percentage replacement.


2019 ◽  
Vol 10 (3) ◽  
pp. 253-258
Author(s):  
S. Jagan

Sustainability and scarcity in resources are the two major issues to be dealt within the present scenario by effective utilization of alternative materials. In this present study, an attempt has been taken to study the effect of supplementary materials such as fly ash and silica fume as a partial replacement to cement and steel slag and M-sand as a replacement to river sand on strength and durability of concrete. In this study, concrete specimens were prepared based on five different mixes by varying the percentages of these supplementary materials. Various mechanical properties like compressive strength, split tensile strength and flexural strength were performed to ascertain the mix with optimum levels of replacement of supplementary materials for cement and fine aggregate. Durability property like water absorption test was performed on the mix with optimum values of strength. Results revealed that mix with higher percentages of steel slag, optimum level of silica fume and fly ash have shown higher strength and lesser permeability in concrete.


2013 ◽  
Vol 31 (3-6) ◽  
pp. 123-134 ◽  
Author(s):  
Velu Saraswathy ◽  
Subbiah P. Karthick

AbstractThe development and use of blended cement is growing rapidly in the construction industry mainly due to the consideration of energy, environment, and conservation of resources. Blended cements are produced using any of the supplementary cementitious materials such as silica fume (SF), fly ash, and ground granulated blast furnace slag. The use of SF in concrete may improve the strength and durability of concrete by creating a denser cement matrix compared with conventional concrete, thereby enhancing the service life of concrete structures. In this article, the effect of SF in concrete is reviewed from the point of view of durability. It includes carbonation, resistivity, chloride permeability/diffusivity, sulfate resistance, and corrosion resistance.


2020 ◽  
Vol 71 (7) ◽  
pp. 775-788
Author(s):  
Quyet Truong Van ◽  
Sang Nguyen Thanh

The utilisation of supplementary cementitious materials (SCMs) is widespread in the concrete industry because of the performance benefits and economic. Ground granulated blast furnace slag (GGBFS) and fly ash (FA) have been used as the SCMs in concrete for reducing the weight of cement and improving durability properties. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40% and 60% by weight were used in fine-grained concrete. The ternary binders containing GGBFS and FA at cement replacement ratio of 60% by weight have also evaluated. Flexural and compressive strength test, rapid chloride permeability test and under-water abrasion test were performed. Experimental results show that the increase in concrete strength with GGBFS contents from 20% to 40% but at a higher period of maturity (56 days and more). The chloride permeability the under-water abrasion reduced with the increasing cement replacement by GGBFS or a combination of GGBFS and FA


2021 ◽  
Vol 11 (9) ◽  
pp. 4028
Author(s):  
Asghar Gholizadeh Vayghan ◽  
Liesbeth Horckmans ◽  
Ruben Snellings ◽  
Arne Peys ◽  
Priscilla Teck ◽  
...  

This research investigated the possibility of using metallurgical slags from the copper and lead industries as partial replacement for cement. The studied slags were fayalitic, having a mainly ferro-silicate composition with minor contents of Al2O3 and CaO. The slags were treated at 1200–1300 °C (to reduce the heavy metal content) and then granulated in water to promote the formation of reactive phases. A full hydration study was carried out to assess the kinetics of reactions, the phases formed during hydration, the reactivity of the slags and their strength activity as supplementary cementitious material (SCM). The batch-leaching behaviour of cementitious mixtures incorporating treated slags was also investigated. The results showed that all three slags have satisfactory leaching behaviour and similar performance in terms of reactivity and contribution to the strength development. All slags were found to have mediocre reactivity and contribution to strength, especially at early ages. Nonetheless, they passed the minimum mechanical performance requirements and were found to qualify for use in cement.


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