scholarly journals Performance of Self-Compacting Concrete Slab with Grinded Local Rocks

2018 ◽  
Vol 24 (10) ◽  
pp. 88
Author(s):  
Ahlam A. Abbood
Keyword(s):  
Compressive Strength ◽  
Ultimate Load ◽  
Concrete Slab ◽  
Concrete Slabs ◽  
Percentage Increase ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Rock Powder ◽  
Quartzite Powder ◽  
Strength Improvement

The effect of using grinded rocks of (quartzite and porcelanite) as powder of (10 and 20) % replacement by weight of cement for self-compacting concrete slabs was investigated in this study. Five slabs with 15 concrete cubes were tested experimentally at 28 days to study the compressive strength, ultimate load, ultimate deflection, ductility, crack load and steel strain. The test results show that, the compressive strength improvement when replacement of local rock powder reached to (7.3, 4.22) % for (10 and 20) % quartzite powder and (11.3, 16.1) % for (10 and 20) % porcelanite powder, respectively compared to the reference specimen. The ultimate load percentage increase for slabs with (10 and 20) % replacement of quartzite powder was 41.17% and 23.53%, while the slabs with (10 and 20) % replacement of porcelanite powder were 23.53% and 35.3% compared to the reference slab, respectively. The ultimate deflection, ductility, spread cracks and ultimate steel strain for slabs with replacement materials (quartzite and porcelanite) increased significantly compared to the reference slab.  

Flexural Behaviors of Concrete Slab Reinforced with GFRP Bars

2011 ◽  
Vol 243-249 ◽  
pp. 567-572
Author(s):  
Hao Sheng Gu ◽  
Da Yu Zhu
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Slab ◽  
Reinforcement Ratio ◽  
Parameter Analysis ◽  
Concrete Slabs ◽  
Test Results ◽  
Gfrp Bars ◽  
Reinforced Concrete Slabs ◽  
Steel Bars

This paper attempts to reveal the flexural behaviors of concrete slab reinforced with GFRP bars. Through flexural test, the deformation process and failure mode of concrete slabs reinforced with GFRP bars and steel bars are examined, respectively. The deflection, cracking load, ultimate load and concrete strain are compared between two kinds of concrete slabs. From the test results, it is clarified that the moment-deflection curve of GFRP reinforced concrete slab can be divided into two stages. Before concrete cracks the behaviors of two kinds of concrete slabs are almost the same. However, the deflection of concrete slabs reinforced with GFRP bars increases much faster after cracking and the stress-strain diagram is linear up to rupture with no discernible yield point. The ultimate load of concrete slabs reinforced with GFRP bars is 1.2 times of that of concrete slabs reinforced with steel bars. Based on the test results, finite element analysis is performed in order to study the influence of reinforcement ratio. Parameter analysis shows that the flexural rigidity of GFRP reinforced concrete slabs increases with the reinforcement ratio after cracking.

scholarly journals Strengthening of self-compacting reinforced concrete deep beams containing circular openings with CFRP

2018 ◽  
Vol 162 ◽  
pp. 04015
Author(s):  
Nabeel Al-Bayati ◽  
Bassman Muhammad ◽  
Murooj Faek
Keyword(s):  
Ultimate Load ◽  
Test Results ◽  
Load Path ◽  
Deep Beams ◽  
Self Compacting Concrete ◽  
Reinforced Polymer ◽  
Web Reinforcement ◽  
Externally Bonded ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

This paper shows the behavior of reinforced self-compacting concrete deep beams with circular openings strengthened in shear with various arrangements of externally bonded Carbon Fibre Reinforced Polymer (CFRP). Six simply supported deep beams were constructed and tested under two points load up to the failure for this purpose. All tested beams had same geometry, compressive strength, shear span to depth ratio, main flexural and web reinforcement. The variables considered in this study include the influence of fiber orientation, utilizing longitudinal CFRP strips with vertical strips and area of CFRP. The test results indicated that the presence of the circular openings in center of load path reduce stiffness and ultimate strength by about 50% when compared with solid one, also it was found that the externally bonded CFRP can significantly increase the ultimate load and enhance the stiffness of deep beam with openings.

The Effect of Polypropylene Fiber on the Mechanical Properties of Self-Compacting Concrete

2010 ◽  
Vol 168-170 ◽  
pp. 1325-1329
Author(s):  
Ye Ran Zhu ◽  
Jun Cai ◽  
Dong Wang ◽  
Guo Hong Huang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Polypropylene Fiber ◽  
Flexural Properties ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Bending Tests ◽  
Flexural Toughness ◽  
Four Point Bending

This paper investigates the mechanical properties (compressive strength, splitting tensile strength and flexural toughness) of polypropylene fiber reinforced self-compacting concrete (PFRSCC). The effect of the incorporation of polypropylene fiber on the mechanical properties of PFRSCC is determined. Four point bending tests on beam specimens were performed to evaluate the flexural properties of PFRSCC. Test results indicate that flexural toughness and ductility are remarkably improved by the addition of polypropylene fiber.

Development of Splice Connections for Precast Concrete Structures

2014 ◽  
Vol 980 ◽  
pp. 132-136 ◽  
Author(s):  
Ahmad Baharuddin Abd Rahman ◽  
Jen Hua Ling ◽  
Zuhairi Abd Hamid ◽  
Mohd Hanim Osman ◽  
Shahrin Mohammad ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Failure Modes ◽  
Ultimate Load ◽  
Precast Concrete ◽  
Tensile Load ◽  
Test Results ◽  
Steel Bars ◽  
Embedment Length ◽  
Bar Diameter

This paper presents the test results of proposed grouted sleeve connections under increasing tensile load. The objective of this research was to investigate splice connections that could provide tensile strength similar to the full tensile strength of the connected rebars. The parameters varied were splice types, splice length and rebar embedment length. The performance of the splice connection was evaluated based on the load-displacement, ultimate load, displacements and failure modes. The results show that the strength of splice connection depends on the bond strength between sleeve-to-grout and grout-to-rebar; the tensile strength of spliced steel bars and also the tensile strength of sleeve. It is observed that when the grout compressive strength is more than 60N/mm2and bar embedded length is at least 10 bar diameter, the splice connection in BS series is able to provide full tensile strength of the connected rebars.

BEHAVIOR OF M 50 GRADE SELF-COMPACTING CONCRETE DEVELOPED USING PORTLAND SLAG CEMENT AND METAKAOLIN

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Sravya Nalla ◽  
Janardhana Maganti ◽  
Dinakar Pasla
Keyword(s):  
Compressive Strength ◽  
Mineral Admixtures ◽  
Partial Replacement ◽  
Test Results ◽  
Slag Cement ◽  
Self Compacting Concrete ◽  
Destructive Testing ◽  
Compressive Strength Test ◽  
Portland Slag Cement ◽  
Strength And Durability

Self-compacting concrete (SCC) is a revolutionary development in concrete construction. The addition of mineral admixtures like metakaolin, which is a highly reactive pozzolana to the SCC mixes, gives it superior strength and durability. The present work is an effort to study the behavior of M50 grade SCC by partial replacement of Portland Slag Cement (PSC) with metakaolin. Its strength and durability aspects are comparable with a controlled concrete (without replacement of cement). In the present work, a new mix design methodology based on the efficiency of metakaolin is adopted. The optimum percentage replacement of cement with metakaolin is obtained based on compressive strength test results. The influence of metakaolin on the workability, compressive strength, splitting tensile strength and flexural strength of SCC and its behavior when subjected to elevated temperature was investigated through evaluation against controlled concrete and non-destructive testing. From the test results, it was observed that incorporation of metakaolin at an optimum dosage satisfied all the fresh properties of SCC and improved both the strength and durability performance of SCC compared to controlled concrete.

Calculation of Ultimate Loads of Two-Way Reinforced Concrete Slabs

2012 ◽  
Vol 256-259 ◽  
pp. 850-854
Author(s):  
Yong Wang ◽  
Yu Li Dong
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Failure Criteria ◽  
Reinforcement Ratio ◽  
Concrete Slabs ◽  
Test Results ◽  
Simple Method ◽  
Simply Supported ◽  
Reinforced Concrete Slabs

This paper presents the latest developments of a simple method used to determine the ultimate load of two-way simply supported reinforced concrete slabs. Based on the reinforcement ratio, two failure criteria are proposed in the paper. The effectiveness of the developed model is validated through satisfactory comparison with from test results.

Rehabilitation of reinforced concrete slab–column connections

2002 ◽  
Vol 29 (4) ◽  
pp. 602-611 ◽  
Author(s):  
Ehab F El-Salakawy ◽  
Maria Anna Polak ◽  
Khaled A Soudki
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Concrete Slab ◽  
Normal Weight ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Shear Reinforcement ◽  
Reinforced Concrete Slab ◽  
Normal Weight Concrete ◽  
Average Compressive Strength

The paper presents work on punching shear rehabilitation and strengthening of existing slab–column connections. Four full-scale specimens representing slab–column edge connections were built and tested to failure. Three slabs were then repaired and strengthened and tested again. In the originally tested slabs, which were chosen for repair, one slab had an opening in front of the column and contained shear reinforcement, one slab had an opening and no shear reinforcement, and one had no opening and no reinforcement. The dimensions of the slabs were 1540 × 1020 × 120 mm with square columns (250 × 250 mm). The openings in the specimens were square (150 × 150 mm) with the sides parallel to the sides of the column. The slabs were made using normal weight concrete (28-day average compressive strength of 32 MPa) and reinforced with a reinforcement ratio of 0.75%. The slabs were repaired by replacing old-damaged concrete with new concrete of the same properties. Strengthening was carried out using shear studs for the two slabs, which originally did not have shear reinforcement. The rehabilitation increased the punching shear strength (by 26–41%) and the ductility of the connections. All repaired specimens failed in flexure.Key words: concrete slabs, punching shear, rehabilitation, edge connections, openings, studs, repair.

INVESTIGATION OF EFFECTS OF RECYCLED AGGREGATES AND BLAST FURNACE SLAG ON PROPERTIES OF SELF-COMPACTING CONCRETE

2020 ◽  
Vol XVII (3) ◽  
pp. 1-14
Author(s):  
Leila Shahryari ◽  
Maryam Nafisinia ◽  
Mohammad Hadi Fattahi
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Recycled Aggregates ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Coarse Aggregates ◽  
Fine Aggregates ◽  
Negative Effect ◽  
Furnace Slag

The effects of simultaneous use of recycled aggregates and ground blast furnace slag as a percentage of cement-constituting materials on different properties of fresh self-compacting concrete (SCC) are investigated in this study. To this end, three series of SCC mixtures with a fixed volume of cement paste equalling 380 ltr/m3 (2.36 gal/ft3) and the replacement ratio of coarse aggregates (fifty percent and one hundred percent) and total aggregates (zero percent, fifty percent and one hundred percent) were prepared. The water content ratios in the first, second and third series were 0.4, 0.45, and 0.5, respectively. The results of the compressive strength tests for 7-day, 14-day and 28-day cubic specimens and compressive strength and Brazilian test results for 28-day cylindrical specimens were used as control parameters governing the SCC resistive quality. The results of fresh SCC tests (including slump-flow and T50 tests, V-funnel test, and L-box test) showed that the negative effect of recycled fine aggregates on fresh SCC properties is significantly more than that of recycled coarse aggregate. However, recycled SCC with acceptable properties can be obtained with a slight increase in the amount of superplasticisers used in the presence of slag.

scholarly journals Experimental study of the mechanical behavior of self-compacting concrete based on fracture mechanics

2017 ◽  
Vol 10 (3) ◽  
pp. 744-759
Author(s):  
G. O. RIBEIRO ◽  
P. C. GUETTI ◽  
P. SERNA
Keyword(s):  
Compressive Strength ◽  
Fracture Mechanics ◽  
Mechanical Behavior ◽  
Process Zone ◽  
Physical Nonlinearity ◽  
Bending Test ◽  
Maximum Diameter ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Three Point Bending

ABSTRACT Considering the physical nonlinearity of concrete and the fundamentals of fracture mechanics for quasi-brittle materials, the objective of this study was to determine the fracture energy and the length of the fracture process zone (FPZ) as well as the modulus of elasticity, the tensile strength and the compressive strength of self-compacting concrete (SCC) to characterize its mechanical behavior. A series of tests, including a three-point bending test of SCC and conventional vibrated concrete (CVC) specimens, with a notch at mid-span, and tensile and compressive tests were performed. The mechanical parameters obtained from the CVC specimens were considered as a comparative reference. The effect of the following variables was evaluated and considered at two levels: compressive strength (30 and 50 MPa), granular composition (fine and coarse particle size) and maximum diameter of the aggregate (12 and 20 mm). The effect of these variables on the mechanical behaviors of the SCC specimens was evaluated based on the test results of specimens of four types of concrete, which were obtained from the combination of the variables. The bending tests were performed according to the RILEM TC 89-FMT recommendations, which are based on the size-effect method.

The experimental behavior of CFRP-strengthened reinforced concrete slabs with fire protection systems subjected to standard fire exposure

2017 ◽  
Vol 8 (3) ◽  
pp. 238-250
Author(s):  
Saeed Bakhtiyari ◽  
Arsalan Kalali ◽  
Leila Taghi Akbari ◽  
Farhang Farahbod
Keyword(s):  
Fire Resistance ◽  
Fire Protection ◽  
Concrete Slab ◽  
Fiber Reinforced Polymer ◽  
Concrete Slabs ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Content Type ◽  
Reinforced Polymer ◽  
Gravity Load

PurposeThis paper aims to evaluate fire resistance of carbon fiber-reinforced polymer (CFRP)-strengthened concrete slabs in two forms of unprotected and protected against fire. Design/methodology/approachTo achieve the objective, an unstrengthened and two CFRP-strengthened concrete slabs were first subjected to increasing gravity loading until failure. Subsequently, the unstrengthened concrete slab was placed on a furnace and was subjected to a constant service gravity load and then, the temperature of the furnace was increased according to a standard temperature–time curve until the failure of the slab occurred. This slab was strengthened by CFRP with two different amounts and then, in two cases of unprotected and protected against fire, was tested in accordance with the aforementioned method. FindingsThe gravity test results revealed that CFRP strips bonded to concrete slabs increased the load-bearing capacity considerably. So, this method can be suitable for flexural strengthening of concrete slabs. The fire test results showed that because of more load-bearing capacity and subsequently increase in service gravity load, the strengthened concrete slab failed in a short time due to the lack of CFRP resistance against fire. By contrast, the protected specimens resisted the fire in a considerable time. In addition, it was revealed that details of fire protective coating had an important effect on fire resistance duration. Originality/valueIt is notable that in the literature, there is a lack of data on the fire endurance of fiber-reinforced polymer-strengthened concrete slabs alone without any fire protection system. Furthermore, the applicability and effectiveness of a new kind of spray mineral fire protective coatings was evaluated.

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