摘要:

Pastes and mortars of portland cements with varying fineness were studied. The effect of blending the cements with silica fume up to 10% is presented. Thermogravimetry, heat of hydration, X‐ray diffraction, scanning electron microscopy, compressive strengths, and microhardness measurements were used to evaluate the pastes and mortars. The study reveals that properties and strengths of existing portland cements may be enhanced through the addition of silica fume. Coarse cements are benefited greatly through the blending. Energy savings during grinding may be realized through this proces

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19149.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A dynamic loading test at a slow strain rate was made to examine the stable crack‐growth process in silica glass under several environmental conditions. The temperature and humidity influence on the crack‐growth process was investigated in detail. Test results show that the transition from region I to region II occurs at a constant stress intensity factor,K, independent of temperature and humidity. The transitionKvalue was determined to be 0.61 MPa.m1/2. Furthermore, it is clear that the crack‐growth rate is dependent onK, even in regi

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19150.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Thermoelectric coefficient measurements in the system Fe304‐MgFe204were used to determine the cation distributions from 600° to 1300°C. The cation distributions obeyed the relationship:−RTlnKMgCD= 17.4 + 2(−16.4)b(kJ/mol)where KMgCDis the magnesium distribution constant and b is the tetrahedral Fe3+concentration. Low‐temperature distributions are consistent with electrical behavior in the system. High‐temperature thermodynamic activities calculated from our distributions agree with experime

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19151.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19152.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY