Simple Mortar Mixture Proportioning Method for Meeting Minimum and Maximum Flow and Strength Requirements
Date Issued
2012
Abstract
The standard test for strand bond (STSB) test method has been developed to
provide an assessment of the ability of steel prestressing strand to bond with
cementitious materials. The test method is performed by pulling on a steel
strand embedded in a 5 in. diameter steel can filled with mortar. The pullout
strength is measured as the force at 0.1 in. displacement of the untensioned
strand end. The test method currently requires the pullout test to be performed
when the mortar has a compressive strength between 4500 and 5000 psi and
between 22 and 26 hours after mixing. The mortar must also have a flow
between 100 and 125 percent. It can be very difficult for laboratories to
develop a mortar mixture that meets these stringent requirements with their
local cement. This paper presents a simple methodology to develop mortar
mixtures that meet these requirements.
provide an assessment of the ability of steel prestressing strand to bond with
cementitious materials. The test method is performed by pulling on a steel
strand embedded in a 5 in. diameter steel can filled with mortar. The pullout
strength is measured as the force at 0.1 in. displacement of the untensioned
strand end. The test method currently requires the pullout test to be performed
when the mortar has a compressive strength between 4500 and 5000 psi and
between 22 and 26 hours after mixing. The mortar must also have a flow
between 100 and 125 percent. It can be very difficult for laboratories to
develop a mortar mixture that meets these stringent requirements with their
local cement. This paper presents a simple methodology to develop mortar
mixtures that meet these requirements.
Subjects
File(s)![Thumbnail Image]()
Name
2012 PCI NBC Submission.pdf
Size
1004.18 KB
Format
Adobe PDF
Checksum (MD5)
72a86a6dc859fa2dbb1dc99da4e8984b