scholarly journals Execution of Internal Curing Method on Concrete using Pre-Soaked Light Weight Aggregate

2019 ◽  
Vol 8 (9) ◽  
pp. 1345-1349
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Internal Curing ◽  
Light Weight ◽  
Concrete Technology ◽  
Curing Conditions ◽  
Super Plasticizer ◽  
Curing Method ◽  
Flexural Tests

Low water-cement proportion solid mixes have been progressively advanced for use in Civil Engineering foundation because of potential changes in quality and sturdiness. Notwithstanding their expanded quality and diminished porous nature, the structures are defenseless to early-age splitting. Techniques have been created to lessen the breaking in structures. One such strategy is interior curing. The utilization of internal curing operators can give an adequate volume of water by methods for light weight aggregates (LWA). Notwithstanding the volume of water gave by the LWA, the dispersion of the LWA assumes a fundamental part in the viability of interior curing. Recently, high-performance concrete (HPC) has been increasingly used in practice, with the development of concrete technology and the introduction of super plasticizer and silica fume. High performance concrete is a concrete, which has far super quality and sturdiness attributes when contrasted with regular cement. The present examination researches the quality related properties of HPC specimens like flexural quality utilizing silica fume, super plasticizer in the inward curing technique. The mix proportion of 1:1.76:2.52:0.36 is utilized to cast pillars (100mm X 150mm X 1700mm). The HPC specimens are thrown with supplanting of concrete with 12% of silica smoke and expansion of 6%,12%,20% LWA vermiculite. From the pressure test result, ideal rate substitution of LWA is discovered and utilized for throwing bar. The aftereffects of flexural tests directed on shaft specimens demonstrates that 6% substitution of vermiculite gives the higher quality in both water and inward curing conditions.

scholarly journals Effect of different curing conditions on the mechanical properties of reactive powder concrete

2018 ◽  
Vol 162 ◽  
pp. 02014
Author(s):  
Mazin Abdulrahman ◽  
Alyaa Al-Attar ◽  
Marwa Ahmad
Keyword(s):  
Mechanical Properties ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Material Constant ◽  
Hot Water ◽  
Modulus Of Rupture ◽  
Reactive Powder Concrete ◽  
Curing Conditions ◽  
Reactive Powder

Reactive Powder Concrete (RPC) is an ultra-high performance concrete which has superior mechanical and physical properties, and composed of cement and very fine powders such as quartz sand and silica fume with very low water/ binder ratio and Superplasticizer. Heat treatment is a well-known method that can further improve the performance of (RPC). The current research including an experimental study of the effect of different curing conditions on mechanical properties of reactive powder concrete (compressive strength, modulus of rupture and splitting tensile strength), the curing conditions includes three type of curing; immersion in water at temperature of 35 OC (which is considered as the reference-curing situation), immersion in water at temperature of 90 OC for 5 hours daily and curing with hot steam for 5 hours daily) until 28 days according to ASTM C684-99 [8]. This research includes also the study of effect of adding silica fume as percentage of cement weight on mechanical properties of reactive powder concrete for different percentage ratios (5%,10% and 15%). Super plasticizer is also used with ratio of (1.8%) by weight of cementitious material; constant water cement ratio (0.24) was used for all mixes. For each reactive concrete mix, it has been cast into a cubes of (150*150*150) (to conduct the compression test), a cylinders of 150mm diameter with 300mm height (to conduct split test) and prisms of (500*100*100)mm to conduct the modulus of rupture test. The results showed that the best method of curing (according to its enhancing the RPC mechanical properties) is the method of immersion in hot water at temperature 90 OC for the all silica fume percentages, and the best used silica fume percentage was (10%) for the all used curing methods.

scholarly journals Freezing and thawing resistance of internally cured high performance concrete

2018 ◽  
Vol 162 ◽  
pp. 02011
Author(s):  
Muthana Saadi ◽  
Tareq al-Attar ◽  
Shatha Hasan
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Internal Curing ◽  
Fine Aggregate ◽  
Freezing And Thawing ◽  
Cast Concrete ◽  
Curing Method ◽  
Compressive And Flexural Strengths ◽  
Limestone Dust ◽  
Freezing And Thawing Cycles

The behavior of internally cured high performance concrete, HPC, exposed to freezing and thawing cycles, was investigated. Two saturated curing agents, Limestone dust and powder of Porcelanite rock, were used to facilitate internal curing for concrete. These agents were used as partial replacements of fine aggregate in two volumetric percentages, 20 and 30 percent. The cast concrete specimens were separated in two groups according to curing method: water-cured and sealed (only internally-cured) specimens. The concrete specimens were subjected to three exposure systems, F0: without freezing and thawing, and F1 and F2: with 50 and 100 cycles of freezing and thawing, respectively. The freezing and thawing test was done as stipulated by the ASTM C666. The conducted tests for each exposure were: compressive and flexural strengths. The results revealed that internal curing does not enhance the concrete resistance to freezing and thawing cycles. Using saturated agents has increased the moisture content of concrete and makes it more vulnerable to frost action deterioration. Sealed specimens for all investigated mixes showed lower reductions in strength than water-cured ones. The lesser water content of these mixes may be the reason for that behavior.

Effect of Density on Compressive Strength of Ultra High Performance Fiber Reinforced Concrete (UHPFRC) Using Design of Experiment

2016 ◽  
Vol 249 ◽  
pp. 119-124 ◽  
Author(s):  
Mohammad Ali Mosaberpanah ◽  
Ozgur Eren
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
Design Of Experiment ◽  
High Performance ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Fiber Reinforced Concrete ◽  
Ultra High Performance Concrete ◽  
Curing Conditions ◽  
High Performance Fiber

This paper aims to model the effect of density in 7, 14, 28 days on compressive strength of Ultra High Performance Concrete (UHPC) in same compaction and curing conditions by Design of Experiments (DOE) methodology using vary range of 5 variables: Silica fume (SF), Steel Fiber, Cement 42.5, Superplasticizer (SP), and water cemetiotious ratio (w/c).The results shows the significance effect of density on compressive strength of UHPC in different days, The models are valid for the mixes made with 1.0 sand, 0.15-0.30 silica fume amount, 0.70-1.30 cement amount, 0.10- 0.20 steel fiber, 0.04- 0.08 superplasticizer (all values are by sand by weight mass) and 0.18- 0.32 water cementitious ratio.

scholarly journals Effects of Curing Conditions on the MECHANICAL and Microstructural Properties of Ultra-High-Performance Concrete (UHPC) Incorporating Iron Tailing Powder

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 215
Author(s):  
Dong Lu ◽  
Jing Zhong ◽  
Baobao Yan ◽  
Jing Gong ◽  
Ziye He ◽  
...  
Keyword(s):  
High Performance ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Microstructural Properties ◽  
Ultra High Performance Concrete ◽  
Steam Curing ◽  
Curing Conditions ◽  
Curing Method ◽  
Mechanical And Microstructural Properties ◽  
Curing Regime

It has been reported that iron tailing powder (ITP) has the potential to partially replace cement to prepare ultra-high-performance concrete (UHPC). However, the reactivity of ITP particles in concrete largely depends on the curing method. This study investigates the effects of curing conditions on the mechanical and microstructural properties of UHPC containing ITP. To achieve this objective, three research tasks are conducted, including (1) preparing seven concrete formulations by introducing ITP; (2) characterizing their mechanical performance under different curing regimes; and (3) analyzing their microstructure by XRD patterns, FTIR analysis, and SEM observation. The experimental results show that there is an optimum ITP dosage (15%) for their application. The concrete with 15% ITP under standard curing obtains 94.3 MPa at 7 days, their early-age strength could be even further increased by ~30% (warm-water curing) and ~35% (steamed curing). The steam curing regime stimulates the activity of ITP and refines the microstructure. This study demonstrates the potential of replacing Portland cement with ITP in UHPC production.

scholarly journals Compressive Strength and Surface Absorption of High Strength Silica Fume Concrete Under Different Curing Conditions

2007 ◽  
Vol 4 (1) ◽  
pp. 17 ◽  
Author(s):  
S.K. Al-Oraimi ◽  
A.W. Hago ◽  
H.F. Hassan ◽  
R. Taha
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Cementitious Material ◽  
Initial Surface ◽  
Surface Absorption ◽  
Curing Conditions ◽  
Curing Condition

The effect of curing conditions and silica fume replacement on the compressive strength and the initial surface absorption of high performance concrete is reported. The silica fume contents were 5, 10, 15 and 20%, by weight of cement. Four different curing conditions were used: air curing, control curing and two other curing conditions recommended by BS8110 and ACI308-81. The cementitious material (binder) content was constant (400 kg/m3); the water/cement (w/c) ratio was also maintained at a constant value of 0.35; while the water/binder (w/b) ratio ranged from 0.35 to 0.28. The addition of silica fume enhanced the compressive strength significantly up to 30%. The 28-day compressive strength was found to be 69.9 MPa without silica fume and it was determined to be 89.9 MPa with silica fume under the standard curing condition. The 28-day compressive strength results under the control curing condition were found to be higher than the compressive strength for specimens cured under other curing conditions. The surface absorption (ml/m2.s) was found to decrease as the percentage replacement of silica fume was increased. Control curing also decreases the surface absorption of water compared with air curing. Concrete with silica fume was less sensitive to drying than that without silica fume. 

Effect of Copper Slag as a Fine Aggregate on the Durability Characteristics of High-Performance Concrete (HPC) Containing Silica Fume

2020 ◽  
Vol 07 (02) ◽  
pp. 1-10
Author(s):  
Rizwan Ahmad Khan ◽  
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Copper Slag ◽  
Chloride Penetration ◽  
Interfacial Transition Zone ◽  
Fine Aggregate ◽  
Fresh Properties ◽  
Fine Aggregates ◽  
Effect Of Copper

This paper investigates the fresh and durability properties of the high-performance concrete by replacing cement with 15% Silica fume and simultaneously replacing fine aggregates with 25%, 50%, 75% and 100% copper slag at w/b ratio of 0.23. Five mixes were analysed and compared with the standard concrete mix. Fresh properties show an increase in the slump with the increase in the quantity of copper slag to the mix. Sorptivity, chloride penetration, UPV and carbonation results were very encouraging at 50% copper slag replacement levels. Microstructure analysis of these mixes shows the emergence of C-S-H gel for nearly all mixes indicating densification of the interfacial transition zone of the concrete.

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