indicated on the Drawings include exterior curbing and walkways necessary for the repairs or of this portion of the Work and who shall be thoroughly

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1 of this portion of the Work and who shall be thoroughly execution and experienced in placing the types of concrete specified trained finishing of exposed surfaces of the concrete, use only For trained and experienced journeyman concrete finishers. thoroughly provisions of pertinent codes and standards are different Where this Specification, the more stringent provisions shall govern. than CAST-IN-PLACE CONCRETE PAGE 1 GENERAL DESCRIPTION: Work included: Cast-in-place concrete required for this Work is indicated on the Drawings include exterior curbing and walkways necessary for the repairs or and of concrete pavement. replacement QUALITY ASSURANCE: Qualifications: Provide at least one person who shall be present at all times during and who shall direct all work performed under this Section. Codes and Standards: SUBMI'FI-ALS: Materials list: Within 10 days after award of Contract, and before any concrete is delivered the job site, submit to the Owner's Representative a complete list of to proposed to be furnished and installed under this portion of the materials Work, showing manufacturer's name and catalog number of all items such as admixture and the name and address of transit-mix concrete supplier.

2 Keep a together with transit-mix delivery slip certifying contents of concrete, pour, the the record available to the Owner's Representative for his Make upon request. inspection completion of this portion of the Work, deliver the record and Upon delivery slips to the Owner's Representative. the all means necessary to protect cast-in-place concrete materials Use during and after installation and to protect the installed work before, necessary to the approval of the Owner's replacements and at no additional cost to the Owner. Representative concrete, unless otherwise specifically permitted by the Owner's All shall be transit-mixed in accordance with ASTM Representative, concrete shall have the following minimum compressive strength All 28 days and shall be proportioned within the following limits: at a water-cement ratio not exceeding six gallons per sack and have contain entrained air. shall PAGE 2 B. Transit-mix delivery slips: record at the job site showing time and place of each pour of PRODUCT HANDLING: Protection: and materials of all other trades. Replacements: go In the event of damage, immediately make all repairs and PRODUCTS CONCRETE: A. General: C-94. Quality: go Concrete that is subject to freezing temperatures while wet shall

3 Curb Exter. site work: /4 inch to 4 5%+ -1% & cement shall be Portland cement conforming to ASTM C-150, type II, All type V for all concrete in contact with earth, and shall be the product of except All aggregates shall conform to ASTM C-33-71, except as modified 1. herein. Coarse aggregate shall have a minimum cleanliness value of 75 as 2. by State of California Test Method 227-E. determined Fine aggregate shall have a minimum of sand equivalent of 75 as 3. by State of California Test Method determined A. All wood forms used shall be new or like new. PAGE 3 of Min Max size Min sacks of Max slump Entrained Location 28 Days Aggregate Cement In inches Air Concrete C. Cement: manufacturer; the temperature of cement delivered to the plant shall not one 150 degrees F. exceed D. Aggregates: E. Water: All water shall be clean and free from deleterious matter. F. Admixture: All concrete may contain a water reducing admixture, upon approval. FORMING MATERIAL:

4 fabric shall be 10 gauge wire fabric with 6" square openings, ASTM Wire A-186. other materials, not specifically described but required for a complete and proper All of cast-in-place concrete, shall be selected by the Contractor subject to the installation reinforcement, at the time concrete is placed around it, shall be free from rust Steel loose mill scale, oil, paint, and all other coatings which will destroy or reduce scale, to all work on this Section, carefully inspect the installed work Prior all other trades and verify that all such work is complete to the of point where this installation may properly commence. PAGE 4 REINFORCEMENT: Ao Welded Wire Fabric: B. Reinforcing Bars: bars shall be deformed billet steel bars, Reinforcing 40 or Grade 60. Grade ASTM A-615, B. Steel Dowels: Steel dowels shall be round 5/8" x 2' rods greased one end and wrapped with a cardboard sheath or as shown on plan, ASTM A-36. OTHER MATERIALS: approval of the Owner's Representative. CLEANING REINFORCEMENT: bond between steel and concrete. EXECUTION SURFACE CONDITIONS: A. Inspection:

5 that concrete may be placed to the lines and elevations Verify on the Drawings, with all required clearance from indicated the event of discrepancy, immediately notify the Owner's In Representative. not proceed with installation in areas of discrepancy until all such Do have been fully resolved. discrepancies all wood scraps and debris from the areas in which Remove will be placed. concrete excess soil shall be stockpiled on-site or as directed by the Any Representative. Owner's wet the forms (except in Thoroughly or oil them; remove all standing water. weather), Inspection of forms shall be called for before concrete is positively securing and supporting by concrete blocks, metal reinforcement, or spacers, or by metal hangers. chairs PAGE 5 SURFACE CONDITIONS: (Continued) 2. Verify that all items to be embedded in concrete are in place. reinforcement. Discrepancies: PREPARATION: clean the areas to insure proper placement and bonding Thoroughly concrete. of freezing saturate with water all soil that is in contact with concrete Thoroughly maximize expansion of existing soil. to INSPECTION NOTIFICATION: poured. the Owner's Representative at least 48 hours before placing Notify concrete. PLACING REINFORCEMENT: A. General Before the start of concrete placement, accurately place all concrete

6 clear space between bars of not less than one time the Preserve diameter of round bars. normal no case let the clear distance be less than 1 inch or less than In times the maximum size of aggregate. 1-1/3 Concrete below ground Two inches a. against forms: deposited Concrete deposited against b. earth:--. Concrete elsewhere:, As indicated on c. Drawings or the approved by the otherwise Representative Owner's Place bars in horizontal members with minimum a. at splices sufficient to develop the laps strength of the bars. PAGE 6 Clearance: Provide the following minimum concrete covering of reinforcement: Three inches Splicing: Horizontal Bars b. Bars may be wired together at laps. c. Wherever possible, stagger the splices of adjacent bars. d. Splice 30 bar diameters minimum. Wire fabric: all splices in wire fabric at least 1-1/2 meshes wide. Make

7 only those other splices that are indicated on the approved Make Drawings or specifically approved by the Owner's Shop immediately consult the Owner's Representative and obtain required, of new procedure before placing concrete. approval chuting, pumping, and pneumatically conveying concrete, use For equipment of such size and design as to insure a practically only flow of concrete at the delivery end without loss or continuous of materials. separation concrete as dry as possible consistent with good Place never exceeding the maximum specified slump. workmanship, PAGE 7 Splicing (Cont.) 3. Other splices: Representative. Dowels: Place all required steel dowels and securely anchor them into position before the concrete is placed. Obstructions: the event conduits, piping, inserts, sleeves, or any other items interfere In placing reinforcement as indicated on the Drawings or as otherwise with PLACING CONCRETE: A. Method: Convey concrete from mixer to place of final deposit by methods that 1. prevent separation and loss of materials. will Deposit concrete as nearly as possible in its final position to avoid segregation due to re-handling and flowing.

8 placing is once started, carry it on as a continuous operation When placement of the panel or section is complete. until working it around all embedded fixtures and into corners placement, forms. of placement, thoroughly compact the concrete by hand During and by mechanical vibration. tamping not use re-tempered concrete or concrete that has been contaminated by Do materials. foreign PAGE 8 Rate of Placement: concrete at such a rate that concrete is at all times plastic and Place readily between bare bars. flows not pour a greater area at one time than can be properly finished Do checking; this is particularly important during hot or dry without weather. not, in any case, place a slab or curb length greater than 30 Do without construction joints, feet Compaction: Thoroughly consolidate all concrete by suitable means during D. Acceptability: CONSTRUCTION JOINTS: A. Location: Make and locate construction joints as indicated on plans. B. All expansion joints to be" Key Way Type" or approved equal.

9 slabs with a jitterbug to depress the rock, and then push-float Tamp a bull-float as necessary. with provide slab depressions as required for the finishes Carefully on the Drawings. indicated slopes are indicated, slope slabs uniformly to provide even Where for drainage. fall all slabs to a smooth, hard finish. Provide a non-slip broom Trowel in all areas. Unless otherwise indicated on the drawings. finish exposed concrete surface by lightly combing with a finished surface shall be water tested in the presence of the The representative and shall be free of standing water in excess owners Any defective work shall be repaired by contractor at no expense to the Owner. the use of adjacent properties is necessary for accomplishing the work, it shall When the obligation of the Contractor to make all the arrangements with the County for be such use. PAGE 9 LEVELING AND FINISHING: A. General: care that the wet slab meets the screeds accurately and does Take rise above or below them. not go Finishing: (Tolerance from finished grade is not to exceed 1/8") Unless otherwise indicated on the Drawings, make all slabs even and uniform in appearance. Co Exterior finishes: indicated on the Drawings, and where no Where "broom finish" is other exterior slab finish is indicated on the Drawings, finish the medium stiff broom after troweling is complete. D. Testing: of 1/8 inch deep. DEFECTIVE WORK: ADJACENT PREMISES: Otherwise the Contractor shall avoid any encroachment of said properties. It is directly stipulated that the Contractor shall repair and make good any

10 to adjoining properties or remaining structures thereon which is caused by his damage or equipment, including damage or loss to adjoining tenant or property owners, men The Contractor shall exercise precaution at all times for the protection of Ao and property. The County will install warning signs for the working persons The Contractor shall comply with all applicable laws relating to safety go including the safety regulations of the California Division of precautions, provisions of the "Manual of Accident Prevention" as issued by the pertinent General Contractors of America, Inc. The Contractor alone shall Associated responsible for the safety, efficiency, and adequacy of his machinery and be and for any damage which may result from their failure or their methods applicable provisions of the Occupational Safety and Health Administration All (OSHA) shall be adhered to. Prior to opening an excavation, efforts will Code made to determine whether underground installation of sewer, water, or be cables will be encountered, and if so, where such installations are electrical When the excavation approaches the estimated location of such an the exact location shall be determined by careful probing or hand installation, when uncovered, proper supports shall be provided. digging; Remove, as it is generated, all debris resulting from operations. Do not store, A permit debris to accumulate on site. If the Contractor fails to remove or promptly, the County reserves the right to remove debris at debris expense. Contractor's existing elements and areas on site, that are signs, sprinkler systems, lawn areas, plant materials, etc. The utilities, shall repair any damage caused by construction operations. Contractor PAGE 10 ADJACENT PREMISES: (continued) whether to building, paving, concrete walks, merchandise, trade fixtures or plant material. WORKING CONDITIONS: crews and general public. Industrial Safety and CaI/OSHA. The Contractor shall also comply with all improper methods of operations. located. CLEAN-UP: Upon completion of the work, the Contractor shall remove all of his tools and equipment, leaving the entire site in an orderly appearance. PROTECTION: Contractor shall protect all shown on the drawings to remain, including buildings, paving, walks, curbs, END OF SECTION

11 be moist, no water should be standing on the surface when the grout is should applied. the hairline crack has been moistened and thoroughly cleaned, apply the After with a putty knife or pointing trowel. Force the grout into the crack as grout Allow the patched area to dry about two hours. Then, cover the area with a 4. of plastic sheeting or a board. piece Keep the area covered for about five days. Lift the covering once each day and 5. the area with water. sprinkle Undercut the crack to a minimum depth of 1". The depth of the undercutting 3. on the size and depth of the crack to be repaired. depends After the crack has been thoroughly undercut, remove all loose material and 4. the area with a wire brush. brush new concrete patch will hold better if a concrete adhesive is used first. The are many types of concrete adhesives. Acrylic resin-a milky fluid-is one There If you do not use a cement adhesive, thoroughly brush and soak the area to be 7. Moistening the area prevents the old concrete from absorbing all the patched. Specifications for Concrete Patching REPAIRING HAIRLINE CRACKS You can repair hairline cracks in concrete with a grout made of Portland cement 1. water. Add just enough water to the cement to form a thick paste. and Moisten the old concrete along the hairline crack with water for several hours adding the grout. Moistening the concrete prevents it from drawing the before from the grout, which will dry out the mixture. Although the old concrete water much as possible. Then smooth it off so it is level with the original concrete. REPAIRING CRACKS IN SIDEWALKS Cracks in sidewalks that are larger than hairline cracks must be enlarged before they can be satisfactorily repaired. Enlarge the crack along its entire length with a cold chisel and hammer. Make the crack wider at the bottom than at the top. This is known as 2. It helps to bond the new concrete with the older concrete. undercutting. 5. Use a garden hose or a tire pump to blow or wash away the dust in the crack. type. Brush the adhesive into the undercut area and allow it to dry common it becomes tacky. until

12 small patching jobs, use a pre-mixed concrete patch. If you use ready-mix For patch, all you need to add is water. concrete you mix your own concrete patch, use one part Portland cement to two-and- If parts of fine, clean sand. Heavier concrete patch jobs call for one part of a-half the concrete patch mix tightly into the undercut area. Be sure to fill all Tamp completely. areas the mixture begins to set, smooth it down with either a metal trowel or a When float. Use a metal trowel for a smooth finish. For a rough surface, use a wooden the area covered for about five days. Lift the cover once each day to wet Keep the repaired area, permitting the new concrete to cure correctly. down can repair a crack in a concrete driveway in basically the same way as a You in a concrete sidewalk. However, since the driveway must carry heavier crack weight loads, the repaired area must withstand much greater pressure. Use a gravel mix, rather than a sand mix, for repairing concrete driveways. This 2. is one part Portland cement, two parts sand and three parts gravel. mix Thoroughly clean and then undercut the crack. Brush cement adhesive into the 3. area. undercut the cracked area to a greater depth and make the cracks considerably Undercut than when repairing a sidewalk. This extra depth and width increases the wider After the gravel mix has been applied, level the new patch mix off with a trowel 6. float, as you would do when repairing a sidewalk. or in the concrete patch. Although it should be moist, no water should be moisture on the area where the patch is to be applied. standing Portland cement to two parts of sand to three parts of gravel wood float for the finishing job. the patch is completed, allow it to dry for about two hours. Then cover the After area completely with plastic sheeting or boards. patched REPAIRING CONCRETE DRIVEWAYS strength of the repair job. Follow all of the steps outlined previously in repairing a crack in a sidewalk to 5. a crack in a concrete driveway. repair 7. Cover the patched area for five days, wetting it down once each day.

13 of the hole. If the hole is extremely deep and large, you must undercut it as size described and fill the area with a gravel mix. previously shallow, no chipping away is flat-surfaced concrete-such as driveways, patios or using the wire brush on the damaged area, use a lighter brush to remove After loose particles that were dislodged by the wire brush. Then, wash the area the After the cleaning is done, you are ready to apply the latex cement. This usually 6. in 5-lb. cans, with the liquid latex in a smaller can inside a larger can. comes approximately 1/4" layers. Smooth each layer with a up the latex cement 1/4" at a time until it reaches the same level as the Build concrete. Then, smooth out the area with a trowel or float as you would original can repair broken corners on concrete with latex or epoxy cement. A broken You should be thoroughly cleaned and moistened before the mixture is corner up the latex or cement mix 1/4" at a time, as previously described. If the area to be epoxy is quite large, you may need to build a small form to hold the mix while repaired Do not drive an automobile over the patched area for at least five days. This the newly patched section time to dry thoroughly before it must carry the gives load of an automobile or truck. heavy PATCHING HOLES IN WALKS OR DRIVEWAYS How you patch holes in sidewalks and driveways depends on the depth and the Small, shallow holes in sidewalks-can easily be repaired with latex cement. If the hole is small and required. Small, shallow holes need only to be cleaned thoroughly before adding the latex 3. cement. This cleaning can usually be done with a wire brush, which removes all the small 4. of loose concrete when you rub the area thoroughly. pieces to be repaired with a garden hose. the liquid latex into the larger can and thoroughly mix it with the latex Pour to form a heavy paste. Apply this paste to the area to be patched in cement trowel and allow to partially dry before applying the next layer. finish regular concrete. REPAIRING BROKEN CORNERS ON CONCRETE applied. After the corner has been thoroughly brushed and washed, build it is drying.

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