Abstract A method is provided for preventing water bleed in grout for securing post-tensioned tendons, particularly strand tendons employed in the production of prestressed concrete, comprising the use of a gelling agent and a dispersing agent along with cement and water in proportions which provide a pourable, injectable grout composition, the relative proportions of ingredients being selected such that water bleed is controlled or substantially eliminated at pressures less than about 10 psig, at 80 psig, less than 10 percent water loss occurs. The composition preferably contains an expansion agent resulting in positive expansion as required by the specific circumstances of usage. The composition is capable of reducing water bleed to 0 percent at 80 psig differential pressure.
Inventors
👤 M Schupack
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-25 16:43
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
13 words
A method according to claim 1 wherein the tendons are wire strand tendons.
Claim 2
Dependent Claim
30 words
The method according to claim 1 wherein the gelling and dispersing agents are present in amounts greater than about 0.2 percent by weight based on the weight of the cement.
Claim 3
Dependent Claim
27 words
The method according to claim 3 wherein at least one of the gelling and dispersing agents are present in amounts from about 0.3 to 0.5 weight percent.
Claim 4
Dependent Claim
33 words
The method according to claim 4 wherein an expansion agent is present in an amount Which results in positive expansion between 5 and 10 percent of the volume of the original grout composition.
Claim 5
Dependent Claim
21 words
The method according to claim 4 wherein water is used in a weight ratio of water-to-cement of about 0.45 to 0.50.
Claim 6
Dependent Claim
14 words
The method according to claim 4 wherein the dispersing agent comprises a naphthalene sulfonate.
Claim 7
Dependent Claim
24 words
The method according to claim 4 wherein the gelling agent is a composition selected from the group consisting of methyl cellulose and hydroxyethyl cellulose.
Claim 8
Dependent Claim
56 words
The method according to claim 1 wherein the relative proportion of the ingredients of the grout composition is such that no substantial water loss by filtration will occur at bleed filtration pressures less than about 50 psig and water loss by filtration at bleed filtration pressures up to 80 psig is less than about 1 percent.
Claim 9
Dependent Claim
22 words
The method according to claim 9 wherein the gelling agent comprises an hydroxyethyl cellulose and the dispersing agent comprises a naphthalene sulfonate.