Study on Comparison of Self Curing of Concrete by using Normal Coarse Aggregate and Recycled Coarse Aggregate (original) (raw)
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Curing is the name given to the procedure used for promoting the hydration of the cement and consist a control of temperature and moisture movement from the concrete. Curing allows continuous hydration of cement and consequently continuous gain in the strength, once curing stops strength gain of the concrete also stops. Proper moisture conditions are critical because the hydration of the cement virtually ceases when the relative humidity within the capillaries drops below 80%. Proper curing of concrete structures is important to meet performance and durability requirements. In conventional curing this is achieved by external curing applied after mixing, placing and finishing. Self-curing or internal curing is a technique that can be used to provide additional moisture in concrete for more effective hydration of cement and reduced self-desiccation. When concrete is exposed to the environment evaporation of water takes place and loss of moisture will reduce the initial water cement ratio which will result in the incomplete hydration of the cement and hence lowering the quality of the concrete. An experimental study carried out an investigated the use of water-soluble polyethylene glycol (PEG 6000) as self-curing agent. In this study compressive, tensile and flexural strength of self-curing concrete for 7 and 28 days and compared the use of different coarse aggregate (i.e. M35, M45 of normal coarse aggregate and recycled aggregate) and found out optimum strength.
Curing of concrete is defined as providing satisfactory moisture content in concrete during its early ages in order to develop the desired properties of concrete. In conventional curing this is achieved by external supply of water after mixing, placing and finishing of concrete. In practice conventional type of curing is difficult to perform as it shall need a large amount of water, meanwhile scarcity of potable water increases day by day. In order to save water as well as achieve curing several researchers started thinking about developing self-curing agents. Self-curing or internal curing is a technique that can be used to provide additional moisture in concrete for more effective hydration of cement and reduced self-desiccation. Internal curing can be achieved by using saturated light weight aggregate and polyethylene glycol. They provide sufficient moisture to the hydrating cement throughout the cross section of the concrete. This study deals with objective of gaining knowledge in the field of concrete technology which includes the study of self-curing of concrete. The aim of the investigation is to evaluate the use of poly ethylene glycol and light weight fine aggregate as self-curing agent. Self-cured specimens were developed and kept as such without the application of any external curing. In this study compressive strength, flexural strength, split tensile strength of concrete containing self-curing agent is investigated and compared to conventional concrete.
STRENGTH CHARACTERISTICS OF SELF-CURING CONCRETE USING POLYETHYLENE GLYCOL (PEG
Today concrete is most widely used construction material due to its good compressive strength and durability. Depending upon the nature of work the cement, fine aggregate, coarse aggregate and water are mixed in specific proportions to produce plain concrete. Plain concrete needs congenial atmosphere by providing moisture for a minimum period of 28 days for good hydration and to attain desired strength. Any laxity in curing will badly affect the strength and durability of concrete. Self-curing concrete is one of the special concretes in mitigating insufficient curing due to human negligence paucity of water in arid areas, inaccessibility of structures in difficult terrains and in areas where the presence of fluorides in water will badly affect the characteristics of concrete. The present study involves the use of shrinkage reducing admixture polyethylene glycol (PEG 400) in concrete which helps in self curing and helps in better hydration and hence strength. In the present study, the affect of admixture (PEG 400) on compressive strength, split tensile strength and modulus of rupture by varying the percentage of PEG by weight of cement from 0% to 2% were studied both for M20 and M40 mixes. It was found that PEG 400 could help in self curing by giving strength on par with conventional curing. It was also found that 1% of PEG 400 by weight of cement was optimum for M20, while 0.5 % was optimum for M40 grade concretes for achieving maximum strength without compromising workability. Water permeability 2. INTRODUCTION Adequate curing is essential for concrete to obtain structural and durability properties and therefore is one of the most important requirements for optimum concrete performance. Curing of concrete is the process of maintaining the proper moisture conditions to promote optimum cement hydration immediately after placement. With insufficient water, the hydration will not proceed and the resulting concrete may not possess the desirable strength and impermeability. The near surface region of concrete is particularly affected, failing to provide a protective barrier against ingress of harmful agents. Proper curing of concrete structures is important to meet performance and durability requirements. Enough water needs to be present in a concrete mix for the hydration of cement to take place. However, even mix contains enough water, any loss of moisture from the concrete will reduce the initial water cement ratio and result in incomplete hydration of cement especially with the mixes having low water cement ratio. This results in very poor quality of concrete. Proper curing of concrete structures is impotant to meet performance and durability requirements.inconventional curing this is achieved by external curing applied after mixing,placing and finishing. self-curing or internal curing is a technique that can be used to provide additional moisture in concrete for more effective hydration of cement and reduced self-desiccation 2.1 Methods of Conventional Curing Methods of curing concrete fall broadly into the following categories: Ponding or spraying By using covering of wet hessian. Reducing the rate of evaporation of water from concrete surface by covering with a relatively impermeable membrane. Delaying the removal of formwork can also be used to retain some water. Steam curing. 2.2 Difficulties in conventional curing methods For the vertical member it is not possible to keep the surface moist as in case of the flat surfaces. In the places where there is scarcity of water. In the places where manual curing is not possible. A human error may lead to the formation of crack in the member and hence affects strength and durability. 3. Self-curing The ACI-308 Code states that "internal curing refers to the process by which the hydration of cement occurs because of the availability of additional internal water that is not part of the mixing Water." Conventionally, curing concrete means creating conditions such that water is not lost from the surface i.e., curing is taken to happen "from the outside to inside". In contrast, "internal curing" is allowing for curing "from the inside to outside" through the internal reservoirs (in the form of saturated lightweight fine
In today's world, concrete is most popular and widely used material in construction sector due to its good compressive strength and durability. Depending upon its usability the mix proportion (cement, fine aggregate, coarse aggregate and water) are prepared to produce plain concrete. Plain concrete needs ambient atmosphere for curing for a minimum period of 28 days in order to attain desired strength. Any laxity in curing will badly affect the strength and durability of concrete. Self-curing concrete is one of the special concretes in mitigating insufficient curing due to human negligence, paucity of water in arid areas, inaccessibility of structures in difficult terrains and in areas where the presence of fluorides in water will badly affect the characteristics of concrete. The present study involves the use of shrinkage reducing admixtures like POLYETHYLENE GLYCOL (PEG 400) as internal curing compound and CUREFREE-C as external curing compound. These curing compounds are used in concrete which helps in self curing and helps in better hydration and hence good compressive strength. They trap the moisture within the structure and prevent it from evaporation (by creating a thin film or by block the pores containing water) which normally occurs due to the hydration process .In the present study, the affect of curing compounds on compressive strength and flexural strength is studied. From the previous studies by various researchers, we vary the percentage of PEG by weight of cement from 0% to 2% as the dosage of internal curing compound and 0.25% of CUREFREE-C by weight of cement was fixed as the dosage of external curing compound The test results were studied both for M25 and M30 mixes .The results shows that PEG 400 and CUREFREE-C could help in self curing by giving strength on par with that of the conventional curing method.
Review on the Study of Self Curing Concrete
International Journal of Advance Research and Innovative Ideas in Education, 2018
Concrete is one of the most widely used construction material due to its good compressive strength and durability. Depending upon the nature of work the cement, fine aggregate, coarse aggregate and water are mixed in specific proportions to produce conventional concrete. Concrete needs curing for a minimum period of 28 days for achieve good hydration and desired mechanical properties. Any delay in curing will badly affect the strength and durability of concrete. Self-curing concrete is one type of concrete, which cure itself by retaining water (moisture content) in it, Self curing concrete is mainly used in areas where there is an acute shortage of water and the application of water curing is not possible for economic reasons . Conventionally, curing concrete means creating conditions such that water is not evaporated from the surface i.e., curing occurs ‘from the outside to inside’. In contrast, ‘internal curing’is allowing for curing ‘from the inside to outside’ through the intern...
Strength Performance of Self Curing Concrete in Comparison with Conventional Concrete
Journal of emerging technologies and innovative research, 2019
Today concrete is most widely used construction material due to its good compressive strength and durability. The concept of several self-curing agents is to reduce water evaporation from concrete. And hence there is a need to increase the water retention capacity of concrete compared to conventional concrete. It was found that water soluble polymers can be used as selfcuring agents in concrete. The aim of this investigation is to study the strength and durability properties of concrete using watersoluble Polyethylene Glycol as self-curing agent. The function of self-curing agent is to reduce the water evaporation from concrete, and hence they increase the water retention capacity of concrete compared to the conventionally cured concrete. As the water is becoming more scarce now-a-days there is need to implement new techniques to reduce usage of water in construction field. In this study, compressive strength, flexural strength and split tensile strength of concrete containing self-curing agent are investigated and compared with those of conventionally cured concrete. Poly Ethylene Glycol is used as a self curing agent in various percentages as 1%, 1.5% and 2% by weight of cement. M30 concrete mix is used in the study and strength properties of the specimen are determined after 7 days, 14 days and 28 days. Poly ethylene glycol 400 (PEG 400) is a super absorbent polymer which reduces the evaporation of water from the surface of concrete and also helps in water retention. In PEG 400, 400 represent the average molecular weight.
Concrete is most widely used construction materials due to its strength, permanence and durability. Since the concrete is open to atmosphere, the water used in concrete evaporates and the water available in concrete will not be sufficient for effective hydration .If the hydration is to continue unbated, extra water must be added to replenish the loss of water on account of absorption and evaporation. Alternatively, some measures must be taken to prevent the loss of water from the surface of concrete.Therefore ,the curing can be considered as creation of a favourable environment during the early period for uninterrupted hydration. The present study involves the use of shrinkage reducing admixtures like POLYETHYLENE GLYCOL (PEG 400) as internal curing compound .This curing compound used in concrete which helps in self curing and helps in better hydration and hence good compressive strength. They trap the moisture within the structure and prevent it from evaporation which normally occurs due to the hydration process. In the present study, the affect of curing compound on workability (slump and compaction factor) and compressive strength is studied. In this study the percentage of PEG by weight of cement from 0% to 2% as the dosage of internal curing compound was fixed .The test results were studied both for M25 and M40 mixes . It is found through this experiment study that PEG 400 help in self curing by giving strength on par with that of the conventional curing method and also improved workability.
STRENGTH CHARACTERISTICS OF SELF-CURING CONCRETE
IJRET, 2012
Today concrete is most widely used construction material due to its good compressive strength and durability. Depending upon the nature of work the cement, fine aggregate, coarse aggregate and water are mixed in specific proportions to produce plain concrete. Plain concrete needs congenial atmosphere by providing moisture for a minimum period of 28 days for good hydration and to attain desired strength. Any laxity in curing will badly affect the strength and durability of concrete. Self-curing concrete is one of the special concretes in mitigating insufficient curing due to human negligence paucity of water in arid areas, inaccessibility of structures in difficult terrains and in areas where the presence of fluorides in water will badly affect the characteristics of concrete. The present study involves the use of shrinkage reducing admixture polyethylene glycol (PEG 400) in concrete which helps in self curing and helps in better hydration and hence strength. In the present study, the affect of admixture (PEG 400) on compressive strength, split tensile strength and modulus of rupture by varying the percentage of PEG by weight of cement from 0% to 2% were studied both for M20 and M40 mixes. It was found that PEG 400 could help in self curing by giving strength on par with conventional curing. It was also found that 1% of PEG 400 by weight of cement was optimum for M20, while 0.5 % was optimum for M40 grade concretes for achieving maximum strength without compromising workability.
E3S Web of Conferences
Curing of concrete is maintaining satisfactory moisture content in concrete during its early stages in order to develop the desired properties. « However good curing is not always practical in many cases, therefore the need to develop self-curing agents attracted several researchers ». « The concept of several self-curing agents is to reduce water evaporation from concrete and hence increase the water retention capacity of concrete compared to conventional concrete, the use of self-curing agent is very important from the point view that water resources are getting valuable every day ». This project summarizes various aspects of self-curing of concrete which can be of valuable assistance in adopting good construction practices at site. M25 grade concrete cube specimens prepared based on the standards and availability of materials without and with 30% of flyash and quarry dust replaced as cement and fine aggregate and cubes cured by covering them with a external self-curing compound B...
IJERT-Preliminary Studies Of Self Curing Concrete With The Addition Of Polyethylene Glycol
International Journal of Engineering Research and Technology (IJERT), 2013
https://www.ijert.org/preliminary-studies-of-self-curing-concrete-with-the-addition-of-polyethylene-glycol https://www.ijert.org/research/preliminary-studies-of-self-curing-concrete-with-the-addition-of-polyethylene-glycol-IJERTV2IS110065.pdf Concrete is most widely used construction material due to its good compressive strength and durability. Depending upon the nature of work the cement, fine aggregate, coarse aggregate and water are mixed in specific proportions to produce plain concrete. Plain concrete needs congenial atmosphere by providing moisture for a minimum period of 28 days for good hydration and to attain desired strength. The properties of hardened concrete, especially the durability, are greatly influenced by curing since it has a remarkable effect on the hydration of the cement. Any laxity in curing will badly affect the strength and durability of concrete. Self-curing concrete is one of the special concretes in mitigating insufficient curing due to human negligence paucity of water in arid areas, inaccessibility of structures in difficult terrains and in areas where the presence of fluorides in water will badly affect the characteristics of concrete. The present study involves the use of shrinkage reducing admixture polyethylene glycol (PEG 4000) in concrete which helps in self curing and helps in better hydration and hence strength. In the present study, the affect of admixture (PEG 4000) on compressive strength, split tensile strength and modulus of rupture by varying the percentage of PEG by weight of cement from 0% to 2% were studied for M20. It was found that PEG 4000 could help in self curing by giving strength on par with conventional curing. It was also found that 1% of PEG 4000 by weight of cement was optimum for M20 grade concretes for achieving maximum strength without compromising workability.