21
Revision D November 2022
Site Preparation/Foundation
A QuadGuard
®
HS system should be assembled only on an existing or freshly placed and cured
concrete base (
4000 psi [28 MPa]
minimum). Location and orientation of the concrete base and
attenuator must comply with project plans or as otherwise determined by the resident project
engineer.
Recommended dimension and reinforcement specifications for new concrete pads are provided
in Valtir Concrete Pad drawing, supplied with the system. The QuadGuard
®
HS system may also
be assembled on a concrete roadway (minimum 8” [200 mm] thick) measuring at least 12’ [3.6 m]
wide by 50’ [15.24 m] long. Deployment cross-slope shall not exceed 8% (Figure 6) and should
not twist more than 2% over the length of the system; the pad surface shall have a light broom
finish.
Caution:
Accurate placement of all steel rebar is critical to avoid interference with
the Concrete Anchor Bolts.
Warning:
Location of the Backup in relation to nearby objects will affect the
operation of the attenuator. Upon impact, the Fender Panels telescope rearward
and extend beyond the rigid Backup as much as
30” [760 mm]
from their pre-
impact location. Position the Backup so that the rear ends of the last Fender Panels
are a minimum of
30” [760 mm]
forward of objects that would otherwise interfere
with movement of the Panels. Failure to comply with this requirement is likely to
result in system performance which had not been crash tested pursuant to NCHRP
Report 350 criteria and may also cause component damage which will necessitate
maintenance or replacement of the system.
Inspect Shipping
Important:
Before deploying the QuadGuard
®
HS system, check the received
parts against the shipping list supplied with the system. Make sure all parts have
been received.
Figure 6
Cross-Slope
