(a) In all motor vehicle use areas, Portland cement concrete shall be poured and constructed in accordance with the following standards:
(1) The base must be smooth and consist of undisturbed or compacted earth. Stone, gravel, limestone screenings or nonsettling material, approved by the City Engineer may be used as a leveling course. Excavations or trenches under a drive must be compacted or filled with a nonsettling material.
(2) The subgrade or base shall be dampened, if dry, before pouring.
(3) Be reinforced with wire reinforcing mesh having a maximum spacing of six inches in either parallel direction between wires and a minimum wire size of Number 10 U.S. Gauge.
(4) Have a uniform thickness in accordance with the specific standards for the use and district.
(5) Minimum floating and finishing shall be required. A broom finish shall be required. Finishing must be delayed until water sheen (bleed water) has disappeared from the surface.
(6) Curing compound shall be applied immediately after broom finishing, without damaging the surface, according to the manufacturer's recommendation.
(7) In each motor vehicle use area in a Nonresidential District, a four inch underdrain shall be constructed around the perimeter in accordance with the detailed specification in Appendix "C" hereto, unless an alternate drainage plan is approved by the City Engineer.
(b) In all motor vehicle use areas, interlocking concrete paving stones shall be installed in accordance with the following requirements:
(1) Sub-grade soils shall meet or be modified to meet the criteria set forth in NCMA TEK-115, "Concrete Block Pavements- Structural Design".
(2) Sub-base materials and preparation shall meet specifications as set forth in NCMA TEK-115, "Concrete Block Pavements-Structural Design."
(3) The sub-base shall be true to grade with a vertical variation of no more than one-half inch in ten feet.
(4) The leveling course shall be a well graded, nonplastic sand with the gradation range as follows:
Sieve Size | 3/8" | No. 4 | No. 8 | No. 16 | No. 50 | No. 100 | No. 200 |
% Passing | 100 | 95-100 | 80-100 | 50-85 | 10-30 | 5-15 | 0-10 |
(5) The base or bedding sand shall be screeded to a loose thickness of 1" to 1- 1/2" conforming to the contour of the sub-base surface.
(6) All edges of the interlocking concrete paving stone pavement (including the underlying base or leveling course) must be restrained.
(7) String lines shall be used to insure that the paving stones will be set true to line and grade.
(8) The paving stones shall be placed "hand tight" and level on the loose base or leveling course.
(9) A minimum of three passes of a plate vibrator (minimum compactor force of 2,500 pounds for 6 cm stones, and 5,000 pounds for stones 8 cm and thicker) shall be made to set the paving stones in the leveling course, prior to filling the joints with sand. Vibrator must not be passed nearer than one yard from an unrestrained edge.
(10) All voids and joints are to be filled by sweeping and vibrating in sand equal in gradation to the sand in the base or leveling course or slightly finer (one hundred percent (100%) passing the No. 16 sieve and ten percent (10%) passing the No. 200 sieve).
(11) Sweeping and vibration shall be alternately continued until all joints are full.
(Ord. 1991-180. Passed 11-4-91.)
(Ord. 1991-180. Passed 11-4-91.)