scholarly journals Effect of the Interfacial Transition Zone on Basic Mechanical Properties of a Solid Composite Propellant

2018 ◽  
Vol 50 (5) ◽  
pp. 807-817
Author(s):  
L. L. Shen ◽  
Z. B. Shen ◽  
H. R. Cui ◽  
H. Y. Li ◽  
S. J. Zhi
Keyword(s):  
Mechanical Properties ◽  
Transition Zone ◽  
Interfacial Transition Zone ◽  
Composite Propellant ◽  
Solid Composite Propellant

The Influence on High-Temperature Mechanical Properties of Hybrid-Fiber-Reinforced High-Performance Concrete and Microscopic Analysis

2012 ◽  
Vol 226-228 ◽  
pp. 1709-1713
Author(s):  
Lan Yan ◽  
Y.M. Xing ◽  
Ji Jun Li
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Transition Zone ◽  
High Performance ◽  
Room Temperature ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Interfacial Transition Zone ◽  
Hybrid Fiber ◽  
High Temperature Mechanical Properties

This paper investigated the high temperature mechanical properties of the hybrid fiber reinforced high performance concrete (HFHPC) and normal concrete (NC) .After being subjected to different elevated heating temperatures, two kinds of concretes have been tested for the compressive strength, splitting tensile strength and flexural strength of test specimen at room temperature and 200 °C,400 °C,600 °C,800 °C.Microstructure changes of concrete were also observed by using Scanning Electron Microscopy (SEM) after high temperature. The results show that the hybrid fiber can significantly increase mechanical properties of the concrete at room temperature and high temperature. SEM and XRD analysis shows that there is a permeable diffusion layer in the steel fiber surface because of solid state reaction in the Interfacial Transition Zone of steel fiber and concrete. This permeable diffusion layer is white, bright, serrated and mainly consist of FeSi2 and the complex hydrated calcium silicate. The compounds of this layer change the Interfacial Transition Zone structure, enhance bonding capacity of the steel fiber and matrix, and increase the high temperature mechanical properties of concrete.

scholarly journals Effect propylene glycol as a quality improvers for Portland and Portland-limestone cements

2019 ◽  
Vol 4 (1) ◽  
pp. 1-7
Author(s):  
Hashem FS ◽  
Eisa E Hekal ◽  
Abdel M Wahab
Keyword(s):  
Mechanical Properties ◽  
Propylene Glycol ◽  
Transition Zone ◽  
Cement Paste ◽  
Cement Hydration ◽  
Interfacial Transition Zone ◽  
Setting Times ◽  
Sand Particles

The performance of propylene glycol (PG) on the grindability, setting and hardening of Portland (OPC) and Portland-Limestone cements (PLC) was studied. Propylene glycol was added to OPC clinker with percentage ratios; 0, 0.03, 0.04 and 0.05 wt.% of the OPC clinker. PLC was made by replacing 5 and 10 wt. % of OPC with limestone. PG offers better grinding aid performance with higher Blaine areas. Besides, presence of PG shows higher water of consistency and lower initial and final setting times. The mechanical properties of mortar specimens made from OPC and PLC admixed with PG were improved especially in the first 7 days. This explained due to increase in the cement fineness which leads to an increase in the degree of cement hydration, as well as to improvement in the interfacial transition zone between the cement paste and sand particles, thus resulting in an enhancement in the strength. DTA and SEM results confirmed the improved properties achieved due to admixing OPC or PLC with PG.

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