908CONCRETE CURBS, GUTT ERS, SIDEWALKS, AND DRIVEWAYS

1049 through. As soon as a strip of fabric has been laid, it shall be pressed into the coat to eliminate air bubbles. Creases in the fabric shall be smoothed out carefully by pulling the fabri c. The top mopping shall be of such thickness and be so applied as to seal and cover the fabric completely. Waterproofing shall be free from punctures, pockets or folds. Special care shall be taken so that the fabric is completely sealed down at the laps. The waterproofing membrane shall be continuous and unbroken. At joints in the membrane, the laps shall be at least 12 inches. The fabric for making the lap shall be left unmopped until the joint is completed. On horizontal surfaces, not less than 4 gallons in each mop coat shall be used for each 100 square feet of surface, and on vertical surfaces, not less than 5 gallons in each mop coat shall be used for each 100 square feet of surface. Expansion and contraction joints shall be covered with membrane waterproofing as required by the plans. Sections waterproofed shall be protected against mechanical injury, high temperature and chemical action, as soon as possible after application and until final acceptance of the work. 907- 4 Method of Measurement: The project plans will show the estimated quantity of surface area to be dampproofed and/or waterproofed and the contractor shall assure itself that this estimated quantity is substantially correct. 907- 5 Basis of Payment: No direct payment will be made for Dampproofing and Waterproofing Concrete Surfaces. The cost of furnishing and applying all materials shall be considered as included in the contract price paid for concrete of the class treated. DRIVEWAYS : 908- 1 Description: The work under this section shall consist of furnishing all materials and constructing Portland cement concrete curb, curb and gutter , ramp curb, sidewalk, sidewalk ramps, driveways, and valley gutters at the locations TABLE OF CONTENTS INDEX 1050 shown on the project plans in accordance with the details shown on the plans and the requirements of these specifications. 908- 2 Materials: 908- 2.01 Concrete: Concrete shall be Class B concrete conforming to the requirements of Section 1006 of the specifications. 908- 2.02 Expansion Joint Filler : Expansion joint filler shall be 1/2- inch bituminous or nonbituminous preformed strips conforming to the requirements of Subsection 1011- 6 of the specifications. 908- 2.03 Concrete Curing Compound: Curing compound shall be liquid membrane- forming compound conforming to the requirements of Subsection 1006- 6.01(C) of the specifications. 908- 2.04 Detectable Warning Strip: Detectable warning strips shall consist of a pre -fabricated mat with truncated domes aligned in a square grid matrix on a flat substrate, or other pre -fabricated materials meeting the requir ements of the Standard Drawings. Detectable warning strips shall contrast visually with the sidewalk ramp, and shall conform to the current requirements of the Americans with Disabilities Act Accessibility Guidelines (ADAAG). Detectable warning strips shall be pre- fabricated from durable material approved by the Department. All detectable warning strips installed within the project limits shall be the same type, unless shown otherwise on plans or approved by the Engineer. Pre-fabricated detectable warning strips approved for use are shown on the Department’s Approved Products List (APL) . T he most current version of the APL is available on the internet from the ADOT Research Cen ter, through the Product Evaluation Program. Pre-fabricated detectible warning strips not listed on the APL may be considered for use in accordance with the requirements of Subsection 106.14 of the specifications. 908- 3 Construction Requir ements: The subgrade shall be constructed in reasonably close conformity to the lines and grades established or shown on the project plans. Prior to placing concrete curb, curb and gutter, driveway, valley gutter, sidewalk ramp, or sidewalk, the material on which they are to be placed TABLE OF CONTENTS INDEX 1051 shall be compacted to a depth of at least 6 inches to a density of not less than 95 percent of the maximum density determined in accordance with the requirements of the applicable test methods of the ADOT Materials T esting Manual as directed and approved by the Engineer. All soft or unsuitable material shall be removed to a depth of not less than 6 inches below subgrade and replaced with material approved by the Engineer. Single curb, curb and gutter, and sidewalk shall be constructed either by the use of conventional fixed forms or by slip- form curb and sidewalk placing machines. Weather and temperature limitations for the placement of concrete shall be in accordance with the requirements of Subsection 1006- 5 of the specifications. Forms shall be maintained at all times in good condition as to accuracy of shape, strength, rigidity and smoothness of surface. The depth of face forms for concrete curbs shall be equal to the full face height of the curb. All other forms shall be set to form the full depth of all edges not formed by adjacent concrete. Unsatisfactory forms shall not be used. Forms shall be set in reasona bly close conformity to the dimensions, lines and grades shown on the project plans or established by the Engineer and be securely staked in position. Clamps, spreaders, and braces shall be used where required to ensure rigid forms. When the roadway secti on slopes away from the gutter, the slope of the gutter shall be formed to match the roadway cross slope. The subgrade and forms shall be watered immediately before placing concrete. Concrete shall be placed in the forms and thoroughly consolidated. The concrete shall be consolidated by means of approved mechanical vibrators or by tamping or spading by hand. The fresh concrete shall be struck off so the surface will be at the proper elevation when the concrete is consolidated. Concrete shall be thoroughly worked so that the coarse aggregate is below the surface. The surface shall then be finished to grade and cross- section with a float, troweled smooth and then given a final fine brush finish. The exposed edges shall be tooled to a 1/4- inch radius unless a larger radius is indicated on the plans. When concrete placed in curb has set sufficiently so that it will not slump, the front face form shall be removed. The gutter, front face, and top of curb shall be troweled smooth and then given a final fine brush finish with brush strokes parallel to the lines of curb and gutter. The exposed edges shall be tooled to a 1/4- inch radius. TABLE OF CONTENTS INDEX 1052 Expansion joints shall be constructed at tangent points of curb returns, at structures, and at a maximum of 60- foot intervals. Expansion joints shall be constructed between sidewalks and driveways, between sidewalks and abutting structures, around poles, posts, boxes, and other fixtures that protrude through the sidewalk. Expansion joints shall match as nearly as possible to the joints in the adjacent pavement or existing concrete curb and sidewalk. Joint filler shall be placed vertically and extend full depth beginning 3/16 inch below the surface of the concrete being placed. During the placing and tamping of concrete, the filler shall be restrained in its proper position. Edges of the concrete at expansion joints shall be tooled to a 1/4- inch radius. Contraction joints (weakened- plane joints) shall be constructed at a max imum of 15- foot intervals in curb and gutter and sidewalks and shall coincide with contraction joints in adjacent pavement or existing concrete curb and sidewalk. A contraction joint shall be constructed along the center of driveway entrances 20 feet wide or greater. Longitudinal contraction joints shall be constructed in the center of sidewalk having a width greater than 7 feet. Contraction joints shall either be formed or sawed. Formed contraction joints shall be constructed by parting the large aggregates in the fresh concrete with a straightedge to a depth of 2 inches. The final joint finishing shall be accomplished with a jointer tool having a radius of 1/4 inch leaving a finished joint depth of a minimum of 3/4 inch. Sawed joints shall be sawed to a depth of 2 inches or one- third the thickness of the concrete, whichever is greater. Scoring lines, where required, shall have a minimum depth of 1/4 inch and a radius of 1/8 inch. Where longitudinal scoring lines are required, they shall be parallel to, or concentric with, the lines of the work. Forms shall be thoroughly cleaned each time they are used and shall be coated with a light oil as required to prevent the concrete from adhering to them. If slip -form equipment is used to construct curb and gutter and sidewalk, such equipment shall be designed specifically for the work. The results shall be equal to or better than that produ ced by the use of fixed forms. If the results are not satisfactory to the Engineer, the use of the equipment shall be discontinued. All applicable requirements of construction by use of fixed forms shall apply to the use of slip- form equipment. The slip- form equipment shall be controlled as to line and grade by means of automatic sensing and control devices such that the machine automatically senses and follows either a taut guide line or other reference, performing any necessary corrective maneuvers in order to establish the correct grade and alignment. The contractor shall set the guide line from survey marks. TABLE OF CONTENTS INDEX 1053 Immediately following the required finishing operations, one or more applications of curing compound shall be applied to all exposed surfaces. The curing compound shall be applied at the rate of not less than 1 gallon per 150 square feet of surface area, and in such manner as to entirely cover and seal all exposed surfaces of concrete with a uniform film. The surface of concrete sidewalk shall be tested with a 10- foot straightedge. Any deviation in excess of 1/4 inch shall be corrected at no additional expense to the Department. The face, top, back, and flow line of the curb and gutter shall be tested with a 10- foot straightedge or curve template, longitudinally along the surface. Any deviation in excess of 1/4 inch shall be corrected at no additional expense to the Department. No vehicular traffic will be allowed on driveways until the concrete has reached at least 60 perce nt of the required 28- day strength. Before acceptance of the work, all curb and gutter and sidewalk shall be cleaned of all discolorations resulting from the contractor's operations, including, but not limited to, dirt, stains, bitumens, and equipment tire marks. Cleaning may be by abrasive blast methods or by other methods approved by the Engineer. The top surface of detectable warning strips, exclusive of the truncated domes, shall be within ± 1/16 inch of the sidewalk ramp surface in accordance with the requirements of the ADAAG. Detectable warning strips shall be installed in accordance with manufacturer’s instructions and current industry practice. In case of discrepancy the manufacturer’s instructions shall govern. 908- 4 Method of Measurement: Concrete single curb and curb and gutter will be measured by the linear foot along the flow line. Lengths of depressed curb and depressed curb and gutter at driveway and sidewalk ramp locations will be included in the measurement. Lengths of curb transition and terminal, and curb and gutter transition and terminal will be included in the measurement. Lengths occupied by catch basins will be excluded from the measurement. No measurement will be made for ramp curb. Concrete sidewalks, driveways, and valley gutter will be measured by the square foot of area constructed. Areas occupied by catch basins will be excluded from the measurement. TABLE OF CONTENTS INDEX