Flexural bond strength/low air/workability additive for mortar cement
AssigneeHercules Incorporated
InventorsArthur L. Anttila, Sung G. Chu, Thomas J. Podlas, Teng-Shau Young
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Abstract
A mortar cement composition is composed of a cement or ground portland cement clinker, ground limestone and/or lime, sand, a sufficient amount of water to render the composition flowable, and at least one water-soluble polymer present in the amount having a lower limit of about 0.001 wt % and an upper limit of about 0.04 wt % based on total dry weight of the ingredients, with the proviso that the extent of adsorption of the polymer onto the cement is less than 50%, and wherein the resulting mortar has 8-16% air content and greater than 70 psi flexural bond strength. This mortar cement composition is for use in building structures in all seismic zones.
Claims46
A mortar cement composition comprising
- a) ground portland cement clinker,
- b) ground limestone and/or lime,
- c) sand,
- d) a sufficient amount of water to render the composition flowable, and
- e) at least one water-soluble polymer present in the amount having a lower limit of about 0.001 wt % and an upper limit of about 0.04 wt % based on total dry weight of the ingredients, said water-soluble polymer being selected from group consisting of hydroxypropylcellulose (HPC), hydroxyethylcellulose (HEC), methylcellulose (MC), hydroxypropylmethylcellulose (HPMC), methylhydroxyethylcellulose (MHEC), hydrophobically modified hydroxyethylcellulose (HMHEC), and mixtures thereof and having a molecular weight lower limit of about 50,000
- with the proviso that the extent of adsorption of the polymer onto the portland cement is less than 50%, and
- wherein the mortar cement has 8-16% air content and greater than 70 psi flexural bond strength according to ASTM C-1329-96.
A method of improving the flexural bond strength of a mortar cement comprising adding to a mortar cement comprising ground portland cement clinker, ground limestone and/or lime, sand, and water, at least one water-soluble polymer in the amount having a lower limit of about 0.001 wt % and an upper limit of about 0.04 wt % based on total dry weight of the ingredients, with the proviso that the extent of adsorption of the polymer onto the ground portland cement clinker is less than 50 wt %, and wherein the resulting mortar has 8-16% air content and greater than 70 psi flexural bond strength.
Dependencies are inferred from the claim text.