repaired prior to insertion or, if determined by the Contracting Officer to
be not repairable, the anchor shall be replaced. Insertion of anchors
shall be in accordance with PTI 4.
[3.3.3
Resin Grouted Anchors
Insertion of resin-grouted anchors shall be in accordance with the resin
manufacturer's written recommendations. Tendons shall be inserted until
contact is made with the first cartridge. The tendon shall then be rotated
and advanced at the rate recommended by the resin grout manufacturer.
After reaching its final position, the tendon shall be rotated as
recommended by the resin grout manufacturer to ensure complete mixing of
the resin.
]3.3.4
Cement Grouted Rock Anchors
**************************************************************************
NOTE: Single stage grouting requires the use of a
bond breaker on the tendon in the free stressing
zone to prevent bonding of the grout to prestressing
steel in the stressing zone. When two-stage
grouting is required, the specification must be
modified to reflect the additional grouting step.
[Second stage grouting shall be performed after the
anchor is stressed, tested, and locked off.]
Rock anchors are normally gravity grouted, however,
in weak or weathered rock pressure grouting may be
used to increase rock-grout bond, to consolidate the
foundation or to provide a grout curtain to restrict
flow of water through the rock. When pressure
grouting is required, the specification shall
include the required grouting pressure. This
grouting would normally take place during the
waterproofing of the holes.
When the ambient rock temperature is known to be
below 10 degrees C (50 degrees F), the provisions of
ACI 306R should be added.
**************************************************************************
Grouting equipment shall be of type and capacity required for successful
installation of the rock anchors. All anchors shall use single stage
grouting to encase the anchor. Grouting shall be performed by a method in
accordance with PTI 4, paragraph 7.6. Grouting shall commence at the
bottom of the grout zone and proceed to the top of the zone. Grouting
shall be gravity flow. [The casing shall be withdrawn as the grouting
proceeds.]
3.3.5
Grouting of Soil Anchors
**************************************************************************
NOTE: Soil anchors in cohesive soils will have
somewhat higher bond strengths when pressure
grouted. Soil anchors in cohesionless soils may
have significantly higher bond strengths depending
on the type of soil. Since the installation and
grouting procedures for soil anchors are highly
dependent on the specific soil conditions, the
SECTION 02490
Page 35
Previous Page
