scholarly journals Use of normal-density high-absorption limestone aggregate as internal curing agent in concrete

2015 ◽  
Vol 42 (11) ◽  
pp. 827-833 ◽  
Author(s):  
Rómel Solís-Carcaño ◽  
Laura V. Terán-Marín ◽  
Eric I. Moreno
Keyword(s):  
Compressive Strength ◽  
Internal Curing ◽  
Hydration Process ◽  
Normal Density ◽  
Curing Agent ◽  
Limestone Aggregate ◽  
Rock Aggregate ◽  
Additional Water ◽  
Natural Aggregates ◽  
High Absorption

A common practice to provide additional water for the hydration process of cement is to use special aggregates that act as agents incorporating water to the concrete (lightweight natural aggregates or polymers). Previous studies have suggested that normal-density high-absorption limestone aggregates may produce a similar effect. The aim was to determine if they can function as an internal curing agent. The methodology consisted of concrete specimens employing two types of aggregates and subjected to three different curing treatments. Results showed similar values of compressive strength and porosity among the concrete cured under wet and dry treatments for the high-absorption limestone aggregate but not for the river rock aggregate. Thus, this effect was attributed to the internal curing properties of the high-absorption limestone aggregate.

scholarly journals Resistencia de concreto con agregado de alta absorción y baja relación a/c

2012 ◽  
Vol 2 (1) ◽  
pp. 21-28
Author(s):  
R. G. Solís ◽  
E. Moreno ◽  
E. Arjona
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Construction Site ◽  
Cement Ratio ◽  
Limestone Aggregate ◽  
Concrete Mixtures ◽  
Water To Cement Ratio ◽  
Maximum Compressive Strength ◽  
Crushed Limestone ◽  
High Absorption

RESUMENLa resistencia del concreto depende de la calidad de la pasta de cemento y de las características de los agregados pétreos. La primera es controlada por la relación agua - cemento, mientras que las propiedades de los agregados generalmente no pueden ser manipuladas ya que se suele utilizar aquellos que están disponibles cerca de la construcción. En muchas regiones rocas con propiedades no deseables son utilizadas como agregado. Por lo tanto, el objetivo de este trabajo fue responder a la pregunta sobre cuál sería la máxima resistencia de diseño que se podría utilizar para concretos fabricados con un tipo específico de agregados obtenidos a partir de la trituración de roca caliza de alta absorción. Se probaron concretos con seis relaciones agua - cemento y dos tamaños de agregado grueso. Se concluyó que con los agregados estudiados es posible fabricar concretos de hasta 500 k/cm2 de f’c.Palabras clave: Absorción; agregados calizos; concreto; relación agua/cemento; resistencia.ABSTRACTConcrete strength depends on the cement paste quality and on the characteristics of the aggregates. The former is controlled by the water to cement ratio, while the properties of the aggregate, in general, cannot be manipulated as it is customary to employ the ones available near the construction site. In many regions rocks with no desirable properties are employed as aggregates. Therefore, the aim of this study was to answer the question about what would that be the maximum compressive strength attainable in concrete made with a specific type of aggregate obtained from crushed limestone of high absorption. Concrete mixtures involved six water to cement ratios and two sizes of coarse aggregate. It was concluded that with this type of aggregate it is possible to made concrete with compressive strength up to 500 k/cm2 of f’c.Key words: Absorption; compressive strength; concrete; limestone aggregate; water/cement ratio.

scholarly journals Efficiency of Sodium Polyacrylate to Improve Durability of Concrete under Adverse Curing Condition

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Tanvir Manzur ◽  
Shohana Iffat ◽  
Munaz Ahmed Noor
Keyword(s):  
Internal Curing ◽  
Curing Agent ◽  
Sodium Polyacrylate ◽  
Curing Process ◽  
Super Absorbent Polymer ◽  
Curing Conditions ◽  
Naturally Occurring ◽  
Additional Water ◽  
Strength And Durability ◽  
Absorbent Polymer

The conventional external curing process requires supply of large amount of water in addition to mixing water as well as strict quality control protocol. However, in a developing country like Bangladesh, many local contractors do not have awareness and required knowledge on importance of curing which often results in weaker concrete with durability issues. Moreover, at times it is difficult to maintain proper external curing process due to nonavailability of water and skilled laborer. Internal curing can be adopted under such scenario since this method is simple and less quality intensive. Usually, naturally occurring porous light weight aggregates (LWA) are used as internal curing agent. However, naturally occurring LWA are not available in many countries like Bangladesh. Under these circumstances, Super Absorbent Polymer (SAP) can be utilized as an alternative internal curing agent. In this study, sodium polyacrylate (SP) as SAP has been used to produce internally cured concrete. Desorption isotherm of SP has been developed to investigate its effectiveness as internal curing agent. Test results showed that internally cured concrete with SP performed better in terms of both strength and durability as compared to control samples when subjected to adverse curing conditions where supply of additional water for external curing was absent.

LWA as Internal Curing Agent to Control Availability of Internal Curing Water in Concrete

2013 ◽  
Vol 1612 ◽  
Author(s):  
Luis Emilio Rendon ◽  
Montserrat Rendon ◽  
Norma Ramirez
Keyword(s):  
Lightweight Aggregate ◽  
Normal Weight ◽  
Internal Curing ◽  
Appreciable Effect ◽  
Curing Agent ◽  
Concrete Compressive Strength ◽  
Concrete Shrinkage ◽  
Coarse Aggregates ◽  
Paste Content ◽  
High Absorption

ABSTRACTThe effectiveness of lightweight aggregate (LWA) as an internal curing agent (ICA) to reduce concrete shrinkage is evaluated for repair concrete used in cultural heritage works (RCCHW) using curing periods of 30 days. Normal weight aggregate is replaced by LWA at volume replacement levels ranging from 10 to 14%. The mixtures contain Portland cement maintaining the paste content at approximately 24.1% of concrete volume. Comparisons are made with mixtures containing low-absorption granite and high-absorption limestone normal weight coarse aggregates. At the replacement levels used in this study, LWA results in a small reduction in concrete density, no appreciable effect on concrete compressive strength, and a decrease in concrete shrinkage for drying periods up to 30 days. With a curing period of 14 days, all mixtures with LWA exhibited less shrinkage than the mixtures with either low- or high-absorption normal weight aggregates.

Feasibility of Bentonite as an Internal Curing Agent in Concrete

2020 ◽  
Vol 13 ◽  
Author(s):  
Abhishek Singh ◽  
Ch. L. Phaneendra ◽  
G. S. Saiveer ◽  
Saurabh Chandravanshi ◽  
Udit Sharma ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Economic Feasibility ◽  
Internal Curing ◽  
Curing Agent ◽  
Field Methods ◽  
Curing Conditions ◽  
Quality Of Water ◽  
Point Test

Abstract:: Background: There is a requirement of internal curing especially in areas where water is scarce and where it is difficult to cure concrete due to inaccessibility of site. About five times higher water is consumed in curing than water mixed in making concrete. Furthermore the quality of water that is to be used for these activities is required to be within certain standards. If the requirement of water can be reduced, it becomes both economically and ecologically viable. Objective: Present research is carried out to determine technical and economic feasibility of bentonite as internal curing agent on properties of concrete in the field. Methods: This paper compares the compressive and flexural strength parameters for standard and bentonite infused concrete and whether this can be considered as a suitable addition in concrete. The flexural strength is measured using four point test. Both tests are carried out in accordance with IS codes. Results: There is an increase in compressive strength for both intermittent and air curing of internally cured concrete in comparison to control concrete. Furthermore air curing of internally cured concrete is comparable to intermittent curing of control concrete. Also compressive strength of intermittent curing concrete with bentonite is comparable with the strength obtained by pond curing of control concrete. Conclusions: The results indicate that bentonite can be considered as a viable addition to concrete, especially in cases of air curing. The use of bentonite is thus recommended more so for air curing and intermittent curing conditions.

scholarly journals The Effect of Different Types of Internal Curing Liquid on the Properties of Alkali-Activated Slag (AAS) Mortar

2021 ◽  
Vol 13 (4) ◽  
pp. 2407
Author(s):  
Guang-Zhu Zhang ◽  
Xiao-Yong Wang ◽  
Tae-Wan Kim ◽  
Jong-Yeon Lim ◽  
Yi Han
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Deionized Water ◽  
Internal Curing ◽  
Control Group ◽  
Alkali Activated Slag ◽  
Different Types ◽  
Naoh Solution ◽  
Activated Slag ◽  
Alkali Activated

This study shows the effect of different types of internal curing liquid on the properties of alkali-activated slag (AAS) mortar. NaOH solution and deionized water were used as the liquid internal curing agents and zeolite sand was the internal curing agent that replaced the standard sand at 15% and 30%, respectively. Experiments on the mechanical properties, hydration kinetics, autogenous shrinkage (AS), internal temperature, internal relative humidity, surface electrical resistivity, ultrasonic pulse velocity (UPV), and setting time were performed. The conclusions are as follows: (1) the setting times of AAS mortars with internal curing by water were longer than those of internal curing by NaOH solution. (2) NaOH solution more effectively reduces the AS of AAS mortars than water when used as an internal curing liquid. (3) The cumulative heat of the AAS mortar when using water for internal curing is substantially reduced compared to the control group. (4) For the AAS mortars with NaOH solution as an internal curing liquid, compared with the control specimen, the compressive strength results are increased. However, a decrease in compressive strength values occurs when water is used as an internal curing liquid in the AAS mortar. (5) The UPV decreases as the content of zeolite sand that replaces the standard sand increases. (6) When internal curing is carried out with water as the internal curing liquid, the surface resistivity values of the AAS mortar are higher than when the alkali solution is used as the internal curing liquid. To sum up, both NaOH and deionized water are effective as internal curing liquids, but the NaOH solution shows a better performance in terms of reducing shrinkage and improving mechanical properties than deionized water.

scholarly journals PENGARUH PENAMBAHAN SERAT ECENG GONDOK PADA KUAT TEKAN PAVING BLOCK K-200

UKaRsT ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 21
Author(s):  
Muttaqin Fauzin Istighfarin ◽  
Rasio Hepiyanto
Keyword(s):  
Compressive Strength ◽  
Water Hyacinth ◽  
Building Materials ◽  
Rigid Pavement ◽  
Cast Concrete ◽  
Additional Water ◽  
Materials Used ◽  
Relationship Of ◽  
Water Hyacinth Fiber

Abstract Paving block is one of the products of building materials used as the top layer of the street structure, compared to other pavements like cast concrete and asphalt, paving block has been widely chosen especially to the streets used to traversed by low-speeed vehicles. This study aims to know and analyze how strong the influence of additional water hyacinth fiber to the compressive strength of K-200 paving block. Method used in this study is experimental method, with the comparison of mix design reffering to the comparison of concrete quality mixture K-200 (SNI 7394-2008). The result is K-200 paving block decreases its compressive strength after given the mixture of water hyacinth fiber. The precentage of the lowest decrease is in the 0,2 mixture of 55,69% and the highest decrease is in the mixture of 0,8 with the decline presentage of of 82,39%. The score of compressive strength for each test object is: Normal of 209,53 kg/cm², 2% of 92,86 kg/cm², 4% of 84,53 kg/cm², 6% of 58,33 kg/cm², and 8% of 36,90 kg/cm². The relationship of non-linear regression can be seen in R² = 1 on  polinomial orde 4. Paving block with with code objects test “Normal” classified as in the quality of paving block B with compressive strength of 209,53 kg/cm² (17,03 Mpa), while for paving block with extra water hyacinth fiber, it is below the compressive strength standard according to SNI 03-0691-1996. Keywords: Rigid Pavement, Paving Block, Water Hyacinth, Compressive Strength.

scholarly journals Influence of Reduced Water Cement Ratio on Behaviour of Concrete Having Plastic Aggregate

2018 ◽  
Vol 4 (12) ◽  
pp. 2971 ◽  
Author(s):  
Saad Tayyab ◽  
Asad Ullah ◽  
Kamal Shah ◽  
Faial Mehmood ◽  
Akhtar Gul
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Stress Strain ◽  
Cement Ratio ◽  
Coarse Aggregates ◽  
Alternative Materials ◽  
Super Plasticizer ◽  
Strain Relationship ◽  
Natural Aggregates ◽  
Reduced Water

The production and use of plastic bottles is increasing tremendously with passing time. These plastic bottles become a problem when they are disposed as they are non-biodegradable. This means that the waste plastic, when dumped, does not decompose naturally and stays in the environment affecting the ecological system. The use of alternative aggregates like Plastic Coarse Aggregate (PCA) is a natural step in solving part of reduction of natural aggregates as well as to solve the issue discussed above. The researchers are trying from half a century to investigate the alternative materials to be replaced in concrete mixture in place of either aggregate or cement.  In this research, the concrete made from plastic waste as coarse aggregates were investigated for compressive strength and Stress-strain relationship. Plastic coarse aggregate have been replaced in place of natural coarse aggregate by different percentages with w/c 0.5, 0.4 and 0.3. The percentage replacement of plastic aggregate in place of mineral coarse aggregate was 25%, 30%, 35% and 40 %. Using Super-plasticizer Chemrite 520-BAS. OPC-53 grade cement was used. Total of forty five Cylinders were prepared based on different combination of Percentage of Plastic aggregate replaced and W/C as discussed above and checked for compressive strength and stress-strain relationship. The compressive strength increases by about 19.25% due to the decrease in W/C from 0.5 to 0.3 for plastic percentage addition of 40%.

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