PRECAST CONCRETE UNDERGROUND UTILITY VAULTS

1 PRECASTCONCRETEUNDERGROUNDUTILITY VAULTSOUTLINE Purpose PRECAST Advantage Purpose of UTILITY VAULTS Uses of UTILITY VAULTS Applicable Standards Structural Design Materials Production Installation NPCA Plant CertificationPURPOSE Provide current and accuratetechnical information as it relates tothe design, production andinstallation of PRECAST CONCRETE ADVANTAGE Available nationwide Environmentally friendly Non-combustible Long life span and durability Delivered and set by manufacturer Less maintenance than CMU Easily designed to withstand traffic or aircraft loading Mass Faster installation large structures easily designed Produced in a controlled environment Cost effectivePURPOSE Provide easy accessto equipment formaintenance.

2 Provide structurallysound enclosure. Provide a secureenclosure for of UTILITY vault Protect vital UNDERGROUND connections and controlsfor UTILITY of UTILITY VAULTS Communications Electricity Gas SteamAPPLICABLE STANDARDS ASTM C 857 Practice for Minimum Structural Design Loadingfor UNDERGROUND PRECAST CONCRETE UtilityStructures ASTM C 858 Specification for UNDERGROUND PRECAST ConcreteUtility Structures ASTM C 891 Practice for Installation of UNDERGROUND PrecastConcrete UTILITY StructuresAPPLICABLE STANDARDS ASTM C 1037 Practice for Inspection ofUnderground PrecastConcrete UTILITY StructuresAPPLICABLE STANDARDS ACI 318 Building Code Requirements for StructuralConcrete AASHTO

3 Specification for Highway Bridges Project Specific RequirementsREFERENCES NPCA BestPractices Manual PRECAST ConcreteUtility VaultManufacturingREFERENCES NPCA QualityControl Manualfor PRECAST Plants Local Codes andRegulationsSTRUCTURAL DESIGN Loading Conditions Surface surcharge Concentrated wheel loads Lateral loads Presumptive soil bearing capacity Buoyant forces Connections and penetrations Point loads Live loads Dead loadsSTRUCTURAL DESIGN CONCRETE Thickness Sufficient to meet minimum reinforcement cover andwithstand design loading conditions. CONCRETE Mix Design CONCRETE Compressive Strength Minimum 4,000 psistrength at 28 days. w/c < .45 (water/cementitious ratio).

4 Quality materials using well-graded aggregates. Air entrained in accordance with ACI 318. Reinforcement Reinforcement design by structural calculations as requiredby code or as proven by CementThe majority of cementused in the manufacturedconcrete products industryis governed by ASTM C 150 Standard Specification forPortland Cement. MATERIALS AggregatesWell-graded, sound,nonporous aggregateconforming to ASTMC 33, StandardSpecification forConcrete Aggregates, is essential in theproduction of high-quality WaterWater for mixing high-qualityprecast CONCRETE shall meetASTM C1602, StandardSpecification for Mixing WaterUsed in the Production ofHydraulic Cement CONCRETE .

5 MATERIALS Admixtures & SupplementaryCementitious Materials (SCMs)Admixtures and SCMs allow the manufacturer to fine-tune and enhance the properties of the CONCRETE mix. Air entraining admixtures per ASTM C 260 improvefreeze-thaw properties while SCMs per ASTM C595and C618 have impacts upon the water content andcan lead to significant improvements in the physicalproperties of the CONCRETE . Today, PRECAST CONCRETE is thehigh-tech material of Reinforcement Reinforcement of concreteis required and must beprovided and designed tomeet structural loading andhandling conditions of Reinforcement Reinforcement types canvary from WWM toconventional rebar tofibers all reinforcementmust comply withapplicable Pre-pour Inspection Trained and qualified plant personnel performinspection before each pour to verify formcleanliness, proper amount of release agent, andreinforcing steel placement and configuration.

6 Post-pour Inspection As an essential part of the production process, thepost-pour inspection verifies product conformanceto project Final Inspection Validation of QualityINSTALLATION Proper installation is absolutelycritical for maintaining the inherentquality of plant-manufacturedconcrete UTILITY structures, andconsiderations include: Proper connections Planning for site conditions Excavation and beddingINSTALLATION vault placement Proper sealing methods Installation of access risers and entry Penetrations Backfilling proceduresNPCA PLANT CERTIFICATION Quality ControlManual to ensure theproduction of qualityprecast products Plant Inspectionsconducted by third-party consultants