scholarly journals Fracture Energy, Fatigue and Creep Properties of Engineered Cementitious Composites Incorporating Fly Ash/Slag with Different Aggregates

2021 ◽  
Author(s):  
Mohamed A. A. Sherir
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Creep Behaviour ◽  
Fatigue Loading ◽  
Experimental Results ◽  
Silica Sand ◽  
Cementitious Composites ◽  
Multiple Cracking ◽  
Engineered Cementitious Composites ◽  
Number Of Cycles

This thesis investigates the influence of microsilica sand and local crushed sand, and different supplementary cementing materials on the mechanical properties of engineered cementitious composites (ECCs). ECC is a special type of high performance fiber reinforced cementitious composite with high ductility which exhibits strain-hardening and multiple-cracking behaviours in tension. The use of local aggregates in ECC production can lower its cost to mitigate the obstacles of wider commercial use. The experimental results showed that multiple-cracking behaviour was developed under fatigue loading for fly ash ECC (FA-ECC) mixtures, and the number of cracks was lower at both lower fatigue stress level and higher fatigue number of cycles. FA-ECC mixtures with silica sand exhibited higher deflection evolution under fatigue loading than FA-ECC mixtures with crushed sand. Based on the experimental results on link slab specimens, both FA-ECC mixtures with silica and crushed sands exhibited almost the same creep behaviour.

scholarly journals Fracture Energy, Fatigue and Creep Properties of Engineered Cementitious Composites Incorporating Fly Ash/Slag with Different Aggregates

2021 ◽  
Author(s):  
Mohamed A. A. Sherir
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Creep Behaviour ◽  
Fatigue Loading ◽  
Experimental Results ◽  
Silica Sand ◽  
Cementitious Composites ◽  
Multiple Cracking ◽  
Engineered Cementitious Composites ◽  
Number Of Cycles

This thesis investigates the influence of microsilica sand and local crushed sand, and different supplementary cementing materials on the mechanical properties of engineered cementitious composites (ECCs). ECC is a special type of high performance fiber reinforced cementitious composite with high ductility which exhibits strain-hardening and multiple-cracking behaviours in tension. The use of local aggregates in ECC production can lower its cost to mitigate the obstacles of wider commercial use. The experimental results showed that multiple-cracking behaviour was developed under fatigue loading for fly ash ECC (FA-ECC) mixtures, and the number of cracks was lower at both lower fatigue stress level and higher fatigue number of cycles. FA-ECC mixtures with silica sand exhibited higher deflection evolution under fatigue loading than FA-ECC mixtures with crushed sand. Based on the experimental results on link slab specimens, both FA-ECC mixtures with silica and crushed sands exhibited almost the same creep behaviour.

scholarly journals Structural Performance of Polymer Fiber Reinforced Engineered Cementitious Composites Subjected to Static and Fatigue Flexural Loading

2021 ◽  
Author(s):  
Mohamed A. A. Sherir ◽  
Khandaker M. A. Hossain ◽  
Mohamed Lachemi
Keyword(s):  
Fly Ash ◽  
Strain Hardening ◽  
Fatigue Loading ◽  
Fiber Reinforced Concrete ◽  
Silica Sand ◽  
Cementitious Composites ◽  
Polymer Fiber ◽  
Fiber Reinforced ◽  
Engineered Cementitious Composites ◽  
Cracking Behavior

This paper presents the influence of silica sand, local crushed sand and different supplementary cementing materials (SCMs) to Portland cement (C) ratio (SCM/C) on the flexural fatigue performance of engineered cementitious composites (ECCs). ECC is a micromechanically-based designed high-performance polymer fiber reinforced concrete with high ductility which exhibits strain-hardening and micro-cracking behavior in tension and flexure. The relative high cost remains an obstacle for wider commercial use of ECC. The replacement of cement by SCMs, and the use of local sand aggregates can lower cost and enhance greenness of the ECC. The main variables of this study were: type and size of aggregates (local crushed or standard silica sand), type of SCMs (fly ash “FA” or slag), SCM/cement ratio of 1.2 or 2.2, three fatigue stress levels and number of fatigue cycles up to 1 million. The study showed that ECC mixtures produced with crushed sand (with high volume of fly ash and slag) exhibited strain hardening behavior (under static loading) with deformation capacities comparable with those made with silica sand. Class F-fly ash combined with crushed sand was the best choice (compared to class CI fly ash and slag) in order to enhance the ECC ductility with slag–ECC mixtures producing lowest deflection capacity. FA–ECC mixtures with silica sand developed more damage under fatigue loading due to higher deflection evolution than FA–ECC mixtures with crushed sand.

scholarly journals Structural Performance of Polymer Fiber Reinforced Engineered Cementitious Composites Subjected to Static and Fatigue Flexural Loading

2021 ◽  
Author(s):  
Mohamed A. A. Sherir ◽  
Khandaker M. A. Hossain ◽  
Mohamed Lachemi
Keyword(s):  
Fly Ash ◽  
Strain Hardening ◽  
Fatigue Loading ◽  
Fiber Reinforced Concrete ◽  
Silica Sand ◽  
Cementitious Composites ◽  
Polymer Fiber ◽  
Fiber Reinforced ◽  
Engineered Cementitious Composites ◽  
Cracking Behavior

This paper presents the influence of silica sand, local crushed sand and different supplementary cementing materials (SCMs) to Portland cement (C) ratio (SCM/C) on the flexural fatigue performance of engineered cementitious composites (ECCs). ECC is a micromechanically-based designed high-performance polymer fiber reinforced concrete with high ductility which exhibits strain-hardening and micro-cracking behavior in tension and flexure. The relative high cost remains an obstacle for wider commercial use of ECC. The replacement of cement by SCMs, and the use of local sand aggregates can lower cost and enhance greenness of the ECC. The main variables of this study were: type and size of aggregates (local crushed or standard silica sand), type of SCMs (fly ash “FA” or slag), SCM/cement ratio of 1.2 or 2.2, three fatigue stress levels and number of fatigue cycles up to 1 million. The study showed that ECC mixtures produced with crushed sand (with high volume of fly ash and slag) exhibited strain hardening behavior (under static loading) with deformation capacities comparable with those made with silica sand. Class F-fly ash combined with crushed sand was the best choice (compared to class CI fly ash and slag) in order to enhance the ECC ductility with slag–ECC mixtures producing lowest deflection capacity. FA–ECC mixtures with silica sand developed more damage under fatigue loading due to higher deflection evolution than FA–ECC mixtures with crushed sand.

scholarly journals Structural Performance And Self-Healing Behaviour Of Engineered Cementitious Composites Subjected To Fatigue Loading

2021 ◽  
Author(s):  
Shirin Ahmad
Keyword(s):  
Fly Ash ◽  
Energy Absorption ◽  
Residual Strength ◽  
Fatigue Loading ◽  
Ash Content ◽  
Evolution Rate ◽  
Cementitious Composites ◽  
Self Healing ◽  
Engineered Cementitious Composites ◽  
Energy Absorbing

This research investigates the effect of fatigue loading on the flexural performance and self-healing behaviour of beams and link slabs made of Engineered Cementitious Composites (ECC). The influences of fly ash content, types/size of sand, MgO agent, fatigue stress level/cycle and age are analyzed based on strength/deflection capacity recovery and residual strength/deflection/energy absorbing capacity. The deflection evolution rate and energy absorption capacity were much higher in ECC link slabs compared to their SCC counterparts. Higher energy absorption and deflection evolution rate were observed in mortar sand based ECC specimens during fatigue loading. ECC link slabs with mortar sand having 55% fly ash content have shown the best self-healing and fatigue performance attaining high residual strength, deflection and energy absorbing capacity of up to 98.3%, 95.4% and 97.1% of control specimens, respectively besides retaining multi-cracking characteristics. This research demonstrates viability of using ECC link slab for construction of joint-free bridges.

scholarly journals Structural Performance And Self-Healing Behaviour Of Engineered Cementitious Composites Subjected To Fatigue Loading

2021 ◽  
Author(s):  
Shirin Ahmad
Keyword(s):  
Fly Ash ◽  
Energy Absorption ◽  
Residual Strength ◽  
Fatigue Loading ◽  
Ash Content ◽  
Evolution Rate ◽  
Cementitious Composites ◽  
Self Healing ◽  
Engineered Cementitious Composites ◽  
Energy Absorbing

This research investigates the effect of fatigue loading on the flexural performance and self-healing behaviour of beams and link slabs made of Engineered Cementitious Composites (ECC). The influences of fly ash content, types/size of sand, MgO agent, fatigue stress level/cycle and age are analyzed based on strength/deflection capacity recovery and residual strength/deflection/energy absorbing capacity. The deflection evolution rate and energy absorption capacity were much higher in ECC link slabs compared to their SCC counterparts. Higher energy absorption and deflection evolution rate were observed in mortar sand based ECC specimens during fatigue loading. ECC link slabs with mortar sand having 55% fly ash content have shown the best self-healing and fatigue performance attaining high residual strength, deflection and energy absorbing capacity of up to 98.3%, 95.4% and 97.1% of control specimens, respectively besides retaining multi-cracking characteristics. This research demonstrates viability of using ECC link slab for construction of joint-free bridges.

Stress-Strain Properties of Engineered Cementitious Composites (ECC) Exposed to Sulfate Dry-Wet Cycle

2020 ◽  
Vol 858 ◽  
pp. 182-187
Author(s):  
Yu Dong Han ◽  
Zhen Bo Wang ◽  
Zi Jie Hong ◽  
Jian Ping Zuo ◽  
Chang Liu ◽  
...  
Keyword(s):  
High Performance ◽  
Strain Softening ◽  
High Performance Concrete ◽  
Cementitious Composites ◽  
Ultra High Performance Concrete ◽  
Stress Strain ◽  
Engineered Cementitious Composites ◽  
Marine Concrete ◽  
New Generation ◽  
Satisfactory Prediction

The brittleness and easiness to crack expose marine concrete to serious durability issues. Engineered Cementitious Composites (ECC), as a new generation of ultra high performance concrete, is expected to overcome the strain-softening properties of traditional concrete and realize function of crack-width control. In this paper, the sulfate erosion of ECC under drying-wetting cycles was modelled in laboratory test. And the compression test on cylinders after exposure to different erosion cycles was implemented to obtain the stress-strain properties. The results disclose that sulfate erosion imposes significant influence on both the nonlinear ascending and descending portions of the stress-strain properties of ECC. As the erosion period extended, ECC strength undergoes an obvious increase. And the descending section of the eroded ECC shows a significant stress drop, which is quite different from that before erosion. Additionally, a simple analytical model was proposed to provide satisfactory prediction of the stress-strain properties of ECC exposed to sulfate erosion.

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