Engineering Properties of Alkali Activated Slag Concrete Under Ambient And Heat Curing

2017 ◽  
Vol 50 (3) ◽  
pp. 161-166 ◽  
Author(s):  
G.Mad huri ◽  
◽  
K. Srinivasa Rao
Keyword(s):  
Engineering Properties ◽  
Alkali Activated Slag ◽  
Heat Curing ◽  
Activated Slag ◽  
Alkali Activated

scholarly journals Effect of Polypropylene Fiber on Properties of Alkali-Activated Slag Mortar

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Yangchen Xu ◽  
Haiming Chen ◽  
Pengju Wang
Keyword(s):  
Water Absorption ◽  
Setting Time ◽  
Impact Resistance ◽  
Polypropylene Fiber ◽  
Engineering Properties ◽  
Alkali Activated Slag ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Activated Slag ◽  
Alkali Activated

Alkali-activated slag (AAS) is becoming an increasingly popular building material due to its excellent engineering properties and low CO2 emissions, but its large shrinkage is an important reason to restrict its application and popularization. This work is aimed to study the possibility of inhibiting the shrinkage of AAS mortar by incorporating polypropylene fiber (PPF). For this, an experimental study was carried out to evaluate the effects of PPF content on setting time, fluidity, physical properties, mechanical properties, impact resistance, and microstructure of AAS mortar. The volume content of PPF is 0.05%, 0.1%, 0.15%, and 0.2%. The working, physical (porosity, water absorption, and bulk density), mechanical, shrinkage, and impact resistance properties of the AAS mortars were evaluated. The results show that incorporating PPF effectively reduces the shrinkage deformation of AAS mortar, significantly improves its impact resistance, enhances its toughness, and slightly improves its compressive strength in the later stage. At the same time, PPF delays the initial setting time of AAS mortar and reduces the fluidity, density, porosity, and water absorption of AAS mortar. SEM results show that the bridging effect of PPF between AAS mortars can inhibit the generation and propagation of cracks, improve the internal microstructure, and enhance the performance of AAS mortar.

scholarly journals Effect of Heat Curing Method on the Mechanical Strength of Alkali-Activated Slag Mortar after High-Temperature Exposure

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1789 ◽  
Author(s):  
Tai Thanh Tran ◽  
Hyuk Kang ◽  
Hyug-Moon Kwon
Keyword(s):  
High Temperature ◽  
Mechanical Strength ◽  
Weight Ratio ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Alkali Activated Slag ◽  
Heat Curing ◽  
Curing Method ◽  
Activated Slag ◽  
Alkali Activated

The aim of this work was to study the mechanical strength and microstructure changes of alkali-activated slag mortar (AAS mortar) after being heat treated in the temperature range of 200–1000 °C. The AAS mortar was cured in the ambient condition (20 ± 5 °C, 60 ± 5% RH) (Relative humidity: RH) and high temperature condition (80 °C) for 27 days with three different heating regimes: curing in a dry oven, curing in sealed plastic bags, and in a steam environment. The activator for the AAS synthesis was a mixture of sodium silicate solution (water glass) and sodium hydroxide (NaOH) with a SiO2/Na2O weight ratio of 1, and a dosage of 4% Na2O by slag weight. Thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) incorporated with energy-dispersive X-ray spectroscopy (EDX) were used to assess the mortar microstructure change. The results revealed that the curing method significantly affected the mechanical strength of AAS at temperatures lower than 800 °C. The heat treatment at late age of 28 days was more beneficial for compressive strength enhancement in specimens without using heat curing methods.

scholarly journals Effect of Dosage of Alkaline Activator on the Properties of Alkali-Activated Slag Pastes

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Zhenzhen Jiao ◽  
Ying Wang ◽  
Wenzhong Zheng ◽  
Wenxuan Huang
Keyword(s):  
Compressive Strength ◽  
Room Temperature ◽  
Setting Time ◽  
Drying Shrinkage ◽  
Engineering Properties ◽  
Alkali Activated Slag ◽  
Alkaline Activator ◽  
Activated Slag ◽  
Good Workability ◽  
Alkali Activated

This study focused on the engineering properties of alkali-activated slag (AAS) pastes prepared by mixing an activator consisting of sodium silicate and sodium hydroxide at room temperature. The water-to-slag ratio of AAS paste was kept constant at 0.35 by mass. AAS pastes were prepared using the activator with five different silicate moduli of 1, 1.2, 1.4, 1.6, and 1.8 and three different Na2O contents of 6%, 8%, and 10%. The results showed that both the silicate moduli and Na2O contents had significant effects on the engineering properties of AAS pastes. All the AAS pastes exhibited properties such as fast setting, good workability, and high early compressive strength. The final setting time varied from 9 to 36 min, and the fluidity was in the range of 147–226 mm. The 1 d compressive strength of all the AAS pastes, which could be easily achieved, had values above 55 MPa, whereas the highest strength obtained was 102 MPa with the silicate modulus of 1 and Na2O content of 8% at room temperature. The drying shrinkage increased as the silicate modulus increased. Furthermore, the hydration products and microstructures of AAS pastes were explained according to the microanalysis methods.

Sign in / Sign up

Export Citation Format

Share Document