Concrete Installation and Replacement 2026

2026-11-03

Construction Methods : • The sub - grade shall be formed by trenching or filling to the required elevation for bottom of concrete or to the bottom of the sub - base , if a sub - base is specified . The subgrade shall be thoroughly tamped or otherwise compacted . A minimum of four inches of Class A sand is required , and if not present , be placed as sub - base . • Before concrete is placed , the sub - grade shall be thoroughly wetted so that the subgrade is uniformly moist , without forming wet or muddy spots . • Sub - base consisting of sand or sand gravel , shall be placed under the structure , to a 4 inch depth . • The forms shall be of wood or metal , straight and free from distortion , and of sufficient strength to resist springing during the process of depositing and finishing the concrete . The forms shall be the full depth of the concrete . They shall be set firmly on the subgrade , true to the required line and grade , and be held in place by adequate stakes , and shall be thoroughly clean and free from foreign material . Approved flexible steel or wood forms may be used for sharp curves or special sections . • Minimum thickness of the concrete is indicated on the drawings provided for each area to be replaced . • The concrete shall be thoroughly spaded along the forms and joints before finishing operations are started . The concrete shall be alternately tamped and struck off with a proper strike board until all voids are removed and the surface has the required grade and cross section . The surface shall be floated with a steel float just enough to produce a smooth surface free from irregularities . • All edges on all sidewalks shall be rounded to a radius of ¼ inch with an approved finishing tool . All joints shall be rounded with an approved double edging tool and have a radius of ¼ inch on each side . The surface shall be brushed lightly to produce a slightly roughened surface and remove the finishing tool marks . Curing of concrete shall be performed by use of one of the appropriate methods as specified for concrete curing agents in the MDOT Standard Specification for Construction dated 2013 in section 903 . • Backfilling shall be performed after the concrete has set sufficiently and the side forms have been removed . The space on both sides of the walk shall be backfilled with sound earth which shall be compacted and trimmed . • Care shall be taken so as to not cause damage to Midland Public Schools property and any adjoining property with equipment or materials . Contractor is responsible for any damage to District or other property caused by their neglect . • Clean - up shall be completed before final acceptance of the work . The Contractor shall clean the street surface , walk , gutters , fences , lawns , private property , right of way , and structures , leaving them in as good a condition as originally found , and shall remove all machinery , tools , surplus materials , temporary buildings and other temporary structures from the site . Concrete Sawing : This Work shall consist of sawing a neat joint with the Contractor . Application may occur primarily at locations where the existing sidewalk joint is not broken . Depth of cut shall be sufficient to ensure a clean breaking joint . Joints : Shall be constructed to provide for expansion and contraction of the concrete as follows : • Joints shall be constructed true to line , with their faces perpendicular to the surface of the concrete . Transverse joints shall be constructed at right angles to the centerline of a sidewalk , and longitudinal joints shall be constructed parallel to centerline , unless otherwise required . When a sidewalk is constructed in partial width slabs , transverse joints in the succeeding slab shall be placed in line with like joints in the adjacent slab . In the case of widening an existing sidewalk , transverse joints shall be placed in line with the like joints in the existing sidewalk . All standard linear sidewalks shall have transverse joints located at five foot intervals . • Expansion joints , ½ inch thick , extending to the full depth of the concrete , shall be placed between the concrete and the back of the abutting curb or gutter at intersections and at those locations where the concrete extends from a building or other rigid structure to the curb , and at intervals of no greater than fifty ( 50 ) feet . Expansion joint material shall be extended to the full depth of the joint and the top shall be slightly below the finished surface . • Contraction joints shall be constructed by dividing the sidewalk into areas of approximately twenty - five square feet unless otherwise shown on the Plans . Insofar as feasible , the unit areas shall be square of not less than nine square feet . Curb Installation : Contractor shall follow curb details found on page eight ( P - 8 ) on the drawings included in this RFP . Protection of concrete : Protection of concrete shall be performed in the following manner : • The Contractor shall be responsible for the proper protection of the sidewalk until sufficiently hard . • Protection against rain – The Contractor shall take such precautions as are necessary to protect the concrete from damage . • Hot weather limitations – Casting of concrete during hot weather shall be limited by the temperature of the concrete at the time of placing . Concrete shall not be cast when the temperature of the concrete is above 90F . Remove and Dispose of Existing Concrete Sidewalk : Removal areas of sidewalk shall be indicated on the attached drawing with approximate measurements . Contractors are responsible for confirming measurements . This work shall consist of removing sidewalk to the nearest broken or sawed joint . Disturbance of the adjacent piece not to be removed will not be allowed . If an adjacent piece is disturbed , Contractor shall remove and replace at Contractor ’ s expense

MITN

2026-04-29