scholarly journals Study on the Relationship of Water Content to Velocities of Elastic Waves and Compressive Strength of Sedimentary Rocks

Author(s):  
Masayasu INOUE ◽  
Michito OMI ◽  
Jun-ichi MORITA
TAPPI Journal ◽  
2009 ◽  
Vol 8 (6) ◽  
pp. 24-28
Author(s):  
CORY JAY WILSON ◽  
BENJAMIN FRANK

TAPPI test T811 is the specified method to ascertain ECT relative to box manufacturer’s certification compliance of corrugated fiberboard under Rule 41/ Alternate Item 222. T811 test sample heights were derived from typical board constructions at the time of the test method’s initial development. New, smaller flute sizes have since been developed, and the use of lighter weight boards has become more common. The T811 test method includes sample specifications for typical A-flute, B-flute, and C-flute singlewall (and doublewall and triplewall) structures, but not for newer thinner E-flute or F-flute structures. This research explores the relationship of ECT sample height to measured compressive load, in an effort to determine valid E-flute and F-flute ECT sample heights for use with the T811 method. Through this process, it identifies challenges present in our use of current ECT test methods as a measure of intrinsic compressive strength for smaller flute structures. The data does not support the use of TAPPI T 811 for ECT measurement for E and F flute structures, and demonstrates inconsistencies with current height specifi-cations for some lightweight B flute.


1979 ◽  
Vol 57 (19) ◽  
pp. 1994-1998 ◽  
Author(s):  
Peter L. Tobiessen ◽  
Nancy G. Slack ◽  
Keith A. Mott

The response of photosynthesis and respiration to drying was measured in four species of epiphytic mosses, Ulota crispa (Hedw.) Brid., Neckera pennata Hedw., Anomodon rugellii (C. Mull.) Keissl., and Plagiomnium cuspidatum (Hedw.) T. Kop., from habitats along a desiccation gradient. There was little difference among the mosses in these responses. The relationship of water content to water potential did differ among the mosses, with Plagiomnium, the facultative epiphyte, showing a typical response of more mesic species and the other three showing a more xeric response, i.e., water potential does not begin to fall steeply until a lower water content is reached in Ulota, Neckera, and Anomodon. Both photosynthesis and respiration in all four moss species were quite sensitive to moderate water stress.


2011 ◽  
Vol 328-330 ◽  
pp. 1475-1482 ◽  
Author(s):  
M. M. A. Abdullah ◽  
H. Kamarudin ◽  
M. Bnhussain ◽  
I. Khairul Nizar ◽  
A.R. Rafiza ◽  
...  

Geopolymer, produced by the reaction of fly ash with an alkaline activator (mixture of Na2SiO3 and NaOH solutions), is an alternative to the use of ordinary Portland cement (OPC) in the construction industry. However, there are salient parameters that affecting the compressive strength of geopolymer. In this research, the effects of various NaOH molarities, Na2SiO3/NaOH ratios, fly ash/alkaline activator, and curing temperature to the strength of geopolymer paste fly ash were studied. Tests were carried out on 50 x 50 x 50 mm cube geopolymer specimens. Compression tests were conducted on the seventh day of testing for all samples. The test results revealed that a 12 M NaOH solution produced the highest compressive strength for the geopolymer. The combination mass ratios of fly ash/alkaline activator and Na2SiO3/NaOH of 2.0 and 2.5, respectively, produced the highest compressive strength after seven days. Geopolymer samples cured at 60 °C produced compressive strength as high as 70 MPa.


2011 ◽  
Vol 233-235 ◽  
pp. 2006-2010 ◽  
Author(s):  
Xiao Qiang Dong ◽  
Xiao Hong Bai ◽  
Yong Kang Lv ◽  
Peng Ju Han

The pH value and SO42- concentration in corrosive environment may affect mechanical property of cemented soil inturn to cause some serious damage to structure. The results of tests show that the unconfined compression strength is decreasing with the increase of H2SO4 solution concentration, increasing with the increase of pH value. The pH value is increasing and the SO42- concentration is decreasing with the increase of corrosive time. So it is concluded that compressive strength is closely rated with the pH value, SO42- concentration of corrosive environment and corrosive time. Finally a equation is set up based on the relationship of compressive strength and factors affected, which contain the reduced coefficient of compressive strength, pH value, SO42- concentration and corrosive time. The calculated and measured values are close so that the equation could be used in practical design for reference.


2011 ◽  
Vol 255-260 ◽  
pp. 4012-4016
Author(s):  
Jun Qing Ma ◽  
You Xi Wang

This paper studies relationship between soil-cement parameters and unconfined compressive strength. The research in tensile strength and deformation modulus of soil-cement is an important basis for soil-cement failure mechanism and intensity theory. They also impact cracks, deformation and durability of cement-soil structure. Shear strength and deformation of soil-cement is important to the destruction analysis and finite element calculations. Therefore it needs to study on tensile strength, shear strength and deformation modulus of soil-cement. Based on previous experiments, the relationship of tensile strength, shear strength, deformation modulus and unconfined compressive strength of soil-cement are quantitatively studied.


Author(s):  
J. Pierzchlewicz

New wall-units have been designed at the Civil Engineering Department of SQU, with improved and reliable thermal insulation properties for construction of buildings in hot climatic conditions. as in the Sultanate of Oman. The thermal resistance of many types of concrete units has been analyzed. Hundreds of various types of the new concrete hollow blocks as well as six-column sections made of these wall-units have been tested in full scale. The relationship of compressive strength of the new concrete hollow blocks, walls made of these units and cube samples has been investigated. The wall columns have been tested under axial load and with various eccentricities. The types of column failure have been studied. The aim of the test was to determine the characteristic compressive strength of the new concrete hollow blocks and the characteristic compressive strength of masonry made of these hollow blocks. The results of the test have shown that the new wall-units could have been used Successfully for construction of the walls in buildings.


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