I am having trouble trying to understand a section in ACI 301-10 "Specifications for Structural Concrete" regarding grout-cleaned rubbed finishes on concrete surfaces, section 5.3.3.4.b. In previous editions of ACI 301, specifically versions 99 and 05, there is a curing note to keep the surface damp for 36 hours. Here is all three texts of the same finish from 99, 05, and 10.
ACI 301-99 and ACI 301-05 state the following verbatim about Grout-Cleaned Finish:
ACI-301-99 5.3.3.4.b Grout-cleaned finish-Begin cleaning operations after contiguous surfaces to be cleaned are completed and accessible. Do not clean surfaces as work progresses. Wet the surface and apply grout consisting of one part Portland cement and one and one-half parts fine sand with enough water to produce the consistency of thick paint. Add white cement as needed to match color of surrounding concrete. Scrub grout into voids, and remove excess grout. When grout whitens, rub the surface and keep surface damp for 36 hr afterward.
ACI-301-05 5.3.3.4.b Grout-cleaned finish-Begin cleaning operations after contiguous surfaces to be cleaned are completed and accessible. Do not clean surfaces as work progresses. Wet the surface and apply grout consisting of one part Portland cement and one and one-half parts fine sand with enough water to produce the consistency of thick paint. Match color of surrounding concrete. Scrub grout into voids, and remove excess grout. When grout whitens, rub the surface and keep surface damp for 36 hr afterward.
Not much deviation between the two. Now see below for ACI 301-10 verbatim:
ACI-301-10 5.3.3.4.b Grout-cleaned finish-When specified, begin cleaning operations after contiguous surfaces are completed and accessible. Do not clean surfaces as Work progresses. Wet the surface and, unless otherwise specified, apply grout consisting of 1 part by volume portland cement and 1-1/2 parts of sand meeting the requirements of ASTM C144 or ASTM C404, with sufficient water to produce the consistency of thick paint. Match color of surrounding concrete. Scrub grout into voids, and remove excess grout.
What I need to know is why does version 10 not list the 36 hour damp cure anymore? Is it no longer required to cure in this manner? Did ACI decide to remove this from finishes so the engineer will now follow what is specified in section 5.3.6.4, Curing methods?
Does anyone have experience with grout-cleaned finish and what did you specify for curing method?
Any help would be greatly appreciated!
ACI 301-99 and ACI 301-05 state the following verbatim about Grout-Cleaned Finish:
ACI-301-99 5.3.3.4.b Grout-cleaned finish-Begin cleaning operations after contiguous surfaces to be cleaned are completed and accessible. Do not clean surfaces as work progresses. Wet the surface and apply grout consisting of one part Portland cement and one and one-half parts fine sand with enough water to produce the consistency of thick paint. Add white cement as needed to match color of surrounding concrete. Scrub grout into voids, and remove excess grout. When grout whitens, rub the surface and keep surface damp for 36 hr afterward.
ACI-301-05 5.3.3.4.b Grout-cleaned finish-Begin cleaning operations after contiguous surfaces to be cleaned are completed and accessible. Do not clean surfaces as work progresses. Wet the surface and apply grout consisting of one part Portland cement and one and one-half parts fine sand with enough water to produce the consistency of thick paint. Match color of surrounding concrete. Scrub grout into voids, and remove excess grout. When grout whitens, rub the surface and keep surface damp for 36 hr afterward.
Not much deviation between the two. Now see below for ACI 301-10 verbatim:
ACI-301-10 5.3.3.4.b Grout-cleaned finish-When specified, begin cleaning operations after contiguous surfaces are completed and accessible. Do not clean surfaces as Work progresses. Wet the surface and, unless otherwise specified, apply grout consisting of 1 part by volume portland cement and 1-1/2 parts of sand meeting the requirements of ASTM C144 or ASTM C404, with sufficient water to produce the consistency of thick paint. Match color of surrounding concrete. Scrub grout into voids, and remove excess grout.
What I need to know is why does version 10 not list the 36 hour damp cure anymore? Is it no longer required to cure in this manner? Did ACI decide to remove this from finishes so the engineer will now follow what is specified in section 5.3.6.4, Curing methods?
Does anyone have experience with grout-cleaned finish and what did you specify for curing method?
Any help would be greatly appreciated!
