Durability of Green High Performance Alkali-Activated Slag Pavement Concrete

2011 ◽  
Vol 99-100 ◽  
pp. 158-161 ◽  
Author(s):  
Yong Gen Wu ◽  
Liang Cai Cai ◽  
Ya Wei Fu
Keyword(s):  
Abrasion Resistance ◽  
High Performance ◽  
Mechanical Performance ◽  
Alkali Activated Slag ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Activated Slag ◽  
Alkali Activated ◽  
Resistance Tests ◽  
Pavement Concrete

Green high performance alkali-activated slag pavement concrete(ASC) was prepared by adding Na2SiO3 and NaOH complex activator in slag. Physical, mechanical performance and durability of ASC were studied by workability, strength, hydrostatics and chlorin ion penetrability, fast freeze-thaw cycle tests and abrasion resistance tests. The results show that slump of ASC exceeds 160mm, fluidity and workability is excellent. 28d compressive and flexural trength of AAC are 91.9MPa and 8.5MPa, 7d compressive and flexural strength are 84.8MPa and 7.6MPa, which belongs to high–early strenth concrete. And its impermeability rank exceeds S40, chlorin ion impermeability is excellent, 6h eletricity is 1751～1894 coulomb, and its anti-frozen rank exceeds F300, which can meet the anti-frozen requirements in frore area. Depth of abrade slot is 0.45～0.96mm, abrasion resistance of ASC is 4.99, so its physical, mechanical performance and durability are superior to traditional portland concrete.

A Preliminary Research on Alkali-Activated Slag Concrete as Tunnel Lining in Severe Frigid Regions

2013 ◽  
Vol 668 ◽  
pp. 65-69 ◽  
Author(s):  
Heng Shu
Keyword(s):  
Frost Damage ◽  
Sem Analysis ◽  
Tunnel Lining ◽  
X Ray Diffraction ◽  
Alkali Activated Slag ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Activated Slag ◽  
Alkali Activated

The main structure materials of tunnel lining are concrete and steel, and the concrete frost damage is a typical degradation phenomenon of the tunnel linings in cold regions. Alkali-activated slag concrete (ASC) has a better freeze-thaw resistance, which can be used for tunnel lining in severe frigid regions. Freeze-thaw resistance, performance mechanism of ASC and microstructure were investigated by freeze-thaw cycle, X-ray diffraction (XRD) and Scanning electron microscope (SEM) analysis. The experimental results show that, ASC has excellent freeze-thaw resistance, and hydration products of ASC are mostly C-S-H, alkaline aluminosilicate. ASC has a good compact degree and uniformity of structure, and its high compressive strength also makes high freeze-thaw resistance. ASC may be selected as tunnel lining production materials in severe frigid regions because of the less reduction in the dynamic elastic modulus and mass loss of concrete.

scholarly journals Investigation of Graphene Derivatives on Electrical Properties of Alkali Activated Slag Composites

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4374
Author(s):  
Wu-Jian Long ◽  
Xuanhan Zhang ◽  
Biqin Dong ◽  
Yuan Fang ◽  
Tao-Hua Ye ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electrical Properties ◽  
Mechanical Performance ◽  
Structural Defects ◽  
Alkali Activated Slag ◽  
Mechanical And Electrical Properties ◽  
Reduced Graphene ◽  
Graphene Derivatives ◽  
Activated Slag ◽  
Alkali Activated

Reduced graphene oxide (rGO) has been widely used to modify the mechanical performance of alkali activated slag composites (AASC); however, the mechanism is still unclear and the electrical properties of rGO reinforced AASC are unknown. Here, the rheological, mechanical, and electrical properties of the AASC containing rGO nanosheets (0, 0.1, 0.2, and 0.3 wt.%) are investigated. Results showed that rGO nanosheets addition can significantly improve the yield stress, plastic viscosity, thixotropy, and compressive strength of the AASC. The addition of 0.3 wt.% rGO nanosheets increased the stress, viscosity, thixotropy, and strength by 186.77 times, 3.68 times, 15.15 times, and 21.02%, respectively. As for electrical properties, the impedance of the AASC increased when the rGO content was less than 0.2 wt.% but decreased with the increasing dosage. In contrast, the dielectric constant and electrical conductivity of the AASC containing rGO nanosheets decreased and then increased, which can be attributed to the abundant interlayer water and the increasing structural defects as the storage sites for charge carriers, respectively. In addition, the effect of graphene oxide (GO) on the AASC is also studied and the results indicated that the agglomeration of GO nanosheets largely inhibited the application of it in the AASC, even with a small dosage.

scholarly journals A Low-Autogenous-Shrinkage Alkali-Activated Slag and Fly Ash Concrete

2020 ◽  
Vol 10 (17) ◽  
pp. 6092
Author(s):  
Zhenming Li ◽  
Xingliang Yao ◽  
Yun Chen ◽  
Tianshi Lu ◽  
Guang Ye
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
High Performance ◽  
Structural Engineering ◽  
Autogenous Shrinkage ◽  
Portland Cement Concrete ◽  
Alkali Activated Slag ◽  
Cracking Potential ◽  
Activated Slag ◽  
Alkali Activated

Alkali-activated slag and fly ash (AASF) materials are emerging as promising alternatives to conventional Portland cement. Despite the superior mechanical properties of AASF materials, they are known to show large autogenous shrinkage, which hinders the wide application of these eco-friendly materials in infrastructure. To mitigate the autogenous shrinkage of AASF, two innovative autogenous-shrinkage-mitigating admixtures, superabsorbent polymers (SAPs) and metakaolin (MK), are applied in this study. The results show that the incorporation of SAPs and MK significantly mitigates autogenous shrinkage and cracking potential of AASF paste and concrete. Moreover, the AASF concrete with SAPs and MK shows enhanced workability and tensile strength-to-compressive strength ratios. These results indicate that SAPs and MK are promising admixtures to make AASF concrete a high-performance alternative to Portland cement concrete in structural engineering.

scholarly journals Effect of Carbonation on Abrasion Resistance of Alkali-Activated Slag with Various Activators

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2812 ◽  
Author(s):  
Hyeong-Ki Kim ◽  
Keum-Il Song ◽  
Jin-Kyu Song ◽  
Jeong Gook Jang
Keyword(s):  
Compressive Strength ◽  
Abrasion Resistance ◽  
Test Method ◽  
Test Results ◽  
Alkali Activated Slag ◽  
Matrix Strength ◽  
Before And After ◽  
Activated Slag ◽  
The Relationship ◽  
Alkali Activated

The effect of carbonation on the abrasion resistance of alkali-activated slag (AAS) was investigated. Various activator sets were selected for synthesizing AAS specimens, and the compressive strength was measured before and after carbonation. The abrasion resistance of the specimens was measured in accordance with the ASTM C944 test method. The relationship between the mass loss caused by abrasion and compressive strength was analyzed to understand the effect of matrix strength on abrasion resistance. Test results showed that the decrease in compressive strength of AAS specimens by carbonation reduced their abrasion resistance. In addition, the abrasion resistance of AAS before and after carbonation was sensitively influenced by activator type. It can be concluded that additional caution is required when using AAS where abrasion may have occurred.

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