Permits & Development - Encroachment(EP)/Driveway(DW) Permits - 2007_EP-07-301 thru EP-07-400_ - EP-07-352

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Nominal Maximum Penetration Slump Penetration Slump Type of Work mm mm mm mm Concrete Pavement 0-25 — 40 — Non-reinforced concrete facilities 0-35 — 50 — Reinforced concrete structures Sections over 300-mm thick 0-35 — 65 — Sections 300-mm thick or less 0-50 — 75 — Concrete placed under water — 150-200 — 225 Cast-in-place concrete piles 93-7 90 130- 180 100 200 • The amount of free water used in concrete shall not exceed 183 kg/m3, plus 20 kg for each required 100 kg of cementitious material in excess of 325 kg/M3. • The term free water is defined as the total water in the mixture minus the water absorbed by the aggregates in reaching a saturated surface-dry condition. • If there are adverse or difficult conditions that affect the placing of concrete,the above specified penetration and free water content limitations may be exceeded providing the Contractor is granted permission by the Engineer in writing to increase the cementitious material content per cubic meter of concrete. The increase in water and cementitious material shall be at a ratio not to exceed 30 kg of water per added 100 kg of cementitious material per cubic meter. Full compensation for additional cementitious material and water added under these conditions shall be considered as included in the contract price paid for the concrete work involved and no additional compensation will be allowed therefor. • The equipment for supplying water to the mixer shall be constructed and arranged so that the amount of water added can be measured accurately. Any method of discharging water into the mixer for a batch shall be accurate within 1.5 percent of the quantity of water required to be added to the mix for any position of the mixer. Tanks used to measure water shall be designed so that water cannot enter while water is being discharged into the mixer and discharge into the mixer shall be made rapidly in one operation without dribbling. All equipment shall be arranged so as to permit checking the amount of water delivered by discharging into measured containers. 90-7 CURING CONCRETE 90-7.01 METHODS OF CURING • Newly placed concrete shall be cured by the methods specified in this Section 90-7.01 and the special provisions. 90-7.01A WATER METHOD • The concrete shall be kept continuously wet by the application of water for a minimum curing period of 7 days after the concrete has been placed. • Cotton mats,rugs, carpets, or earth or sand blankets may be used as a curing medium to retain the moisture during the curing period. • If a curing medium consisting of cotton mats,rugs, carpets,polyethylene sheeting,polyethylene sheering on burlap, or earth or sand blankets is to be used to retain the moisture,the entire surface of the concrete shall be kept damp by applying water with a nozzle that so atomizes the flow that a mist and not a spray is formed,until the surface of the concrete is covered with the curing medium. The moisture from the nozzle shall not be applied under pressure directly upon the concrete and shall not be allowed to accumulate on the concrete in a quantity sufficient to cause a flow or wash the surface. At the expiration of the curing period,the concrete surfaces shall be cleared of all curing media. • At the option of the Contractor, a curing medium consisting of white opaque polyethylene sheering extruded onto burlap may be used to cure concrete structures. The polyethylene sheering shall have a minimum thickness of 100µm, and shall be extruded onto 283.5-gram burlap. • At the option of the Contractor, a curing medium consisting of polyethylene sheeting may be used to cure concrete columns. The polyethylene sheeting shall have a minimum thickness of 250µm achieved in a single layer of material. • If the Contractor chooses to use polyethylene sheeting or polyethylene sheeting on burlap as a curing medium,these media and any joints therein shall be secured as necessary to provide moisture retention and shall be within 75 mm of the concrete at all points along the surface being cured. When these media are used, the temperature of the concrete shall be monitored during curing. If the temperature of the concrete cannot be maintained below 60°C, use of these curing media shall be disallowed. • When concrete bridge decks and flat slabs are to be cured without the use of a curing medium,the entire surface of the bridge deck or slab shall be kept damp by the application of water with an atomizing nozzle as specified above,until the concrete has set, after which the entire surface of the concrete shall be sprinkled continuously with water for a period of not less than 7 days. Contract No. 10-OM7104 84