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Concretee TechnCnology anda CoddesBatching, Mixing,Mixing, andTransportingConcreteTti Ct
ObjectivesStandards Batchingg Mixing Transporting
ASTM C94/C94M/Standard Specification for ReadyReady--Mixed Concrete Materials specificationsOrdering informationSlump tolerancesMeasuring tolerancesMixer/AgitatorrequirementsD liDeliverymethodsth dTesting methods
ASTM C685/C685M/Standard Specification for Concrete Made byVolumetric Batching and Continuous Mixing MaterialsspecificationspOrderinginformationSlump tolerancesMeasuringtolerancesMixing mechanismDelivery methodsTesting methods
ACI 304RGuide for Measuring, Mixing, Transporting,and Placing Concrete Control, handling, and storage ofmaterialsMeasurement and batchingMixing and transportingPlacingVolumetric batching
Batching Process of measuringconcrete mixtureingredients by eithermass or volume Most specificationsrequire batching bymass
Batching by Volume ASTM C685Yi ld checksYieldh kProportioning checksTolerances for batching by volume: Cement, mass% 0 - 4Fi aggregate, mass%Fine% 22Coarse aggregate, mass% 2Admixtures mass or volume% 3Admixtures,Water, mass or volume% 1
Batching by Mass ASTM C94 Batchingg plantpprecision controldischarge operation Plant scales accurate to 0.15%total capacity or0 4% net applied0.4%load
Batching by MassCementitious materials: Measured separately orcombined sequentially Cement first Tolerance at 30% or greater of full scale capacity- 1% required mass Tolerance for loads smaller 30% of scalecapacity- 0- 4% required mass
Batching by MassAggregate: Can be measured individually or combinedTolerancesIndividual loads - 2% of required mass Cumulative loads 30% or more of scale capacity - 1% of requiredmass after each successive weighing less than 30% of scale capacity - the lesser of 0.3% of scale capacity or 3% of required mass
Batching by MassWater: Tolerance - 1% by mass orvolumeIce must be measured bymassWash water remaining intruck mixer drums must beaccurately measuredTotal water tolerance - 3%of the specifiedptotalamount
Batching by MassAdmixtures: Powdered admixtures - mass Liquid admixtures - mass or volume Tolerance - greater of: 3% of total amount required 100% dosage per 50kg (100lbs) ofcement
Inspectingpg Batch PlantsACI 311.5 Project specification complianceStorage standards complianceMaterials testing standardscomplianceTruck operating conditionsEquipment calibrationBatch ticket verification
Mixing and TransportingConcrete Ordering concreteReady mixed concreteMobile batcher mixed concreteRemixing concrete
Ordering ConcreteASTM C94/C685Purchaser specifies: Sizes of coarse aggregate Slump at point of delivery Air content at point of delivery One of three options for remainingparameters
Ordering ConcreteASTM C94/C685Option A—performance based:Purchaser specifies: CompressiveCi strengthtthConcrete producer selects mixproportions.
Ordering ConcreteASTM C94/C685Option B—prescription based:Purchaser specifies mixtureproportions including: Cement content Water content Admixture type and content
Ordering ConcreteASTM C94/C685Option C—mixed option:Purchaser specifies: Compressive strength Cement content Admixture type and contentConcrete producer selects mixproportions.ti
Prescription toPerformance (P2P) Move away from prescriptionspecifications Move towards performancespecifications Focus – final productperformance
P2P - Advantagesg pMore efficient process Encourages cooperation Improved consistency
Ready Mixed Concrete Central-mixed concreteShrink-mixedShrinkmixed concreteTruck-mixed concrete
Central-mixed Concrete Mixed completely ina stationary mixerDelivered ina truck agitator a truck mixeroperatingpg atagitating speed a non-agitatingtruck
Central Mix Plant
Stationaryy Mixers Stationary Mixers Onsite or central mix readymixed concrete plantUsed for complete or shrinkmixingMixer Types ― up to 9 m3 Tilting or non-tiltingnon tilting drumOpen top revolving blade orpaddle
Readyy Mixed ConcreteShrink-mixed Concrete Partial mixing in stationary mixer andcompletedpin truck mixer Stationary mixing time should be minimum Performance tests same as centralcentral-mixedmixedconcrete
Readyy Mixed ConcreteTruck-mixed Concrete Mixed completely in atruck mixer 70 to 100 mixingrevolutions, mixing speed 6-18 rpm Agitating speed 2-6 rpm Discharge before 1½ hoursor 300 revolutions
Mixer TrucksUsed for: pavements, structures,and buildings – distances mustallow discharge of concretewithin 1½ hoursAdvantages: central mixing plantnot needed, discharge is wellcontrolledWatch for: Timing of deliveriesshould suit job organization.Concrete crew and equipmentmust be ready onsite to handleconcrete. Control of quality isnot as good as with centralmixing.mixing
Mixer TrucksRear DischargeFront Discharge
AgitatorTrucksgUsed for: Transportingconcrete for all usesuses. Hauldistances must allowdischarge of concrete within1½ hours.hoursAdvantages:gOperatepusuallyyfrom central mixing plants.Watch for: Timing of deliveriesshould suit job organization.Concrete crew andequipment must be readyonsite to handle concrete.
Non--agitating TruckNonUsed for: Transportconcrete on short haulsover smooth roadways.Advantages: Cost of nonagitating equipment islower than that of truckagitators or mixers.Watch for: Slump should belimited. Possibility ofsegregation Height uponsegregation.discharge is needed.
Mobile Batcher MixedConcrete Auger-typemixerAti Mi i rate dMixingdeterminedi dbby manufacturerf Slump tolerances 40mm (1.5 in)depending on specified slump
Mobile Batcher MixedConcrete UniformityRequirements for Within-Batch Uniformity ofConcreteRange of 2 SamplesAir content, %1.0Air free density16 kg/m3 (1.0 lb/ft3)Sl mpSlumpAvg. 100mm (4 in)25 mm (1 in)Avg. 100mm (4 in)40 mm (1.5 in)Coarse aggregate content, % massconcretet6.07-day strength, % of average7.5
Mobile Batcher Mixer TruckUsed for: Intermittentproduction of concrete atjobsite or small quantitiesjobsite,quantities.Advantages: Combinedmaterials transporter andbatching and mixingyOne-mansystem.operation.Watch for: Good preventivemaintenance program.Materials must be identicalto those in original mixdesign.
Truck Manufacturers Bureaus
Remixingg ConcreteASTM C94Water may be added at jobsite provided: Spec. w/c-ratio is not exceededMeasured slump less than specifiedMixing time or drum revolutions not exceededConcrete is remixedmin. 30 rev. at mixing speed until uniformity is within limits
Transporting ConcreteWatch out for: Delays Labor force managementEquipment selectionRoute planning Early stiffening Flash/False setAccelerated hydration
Transporting ConcreteWatch out for: Drying out Hot and dry weatherLow W/CMUse of silica fume oradmixtures that affect bleedwaterSegregation Cohesive mixturePlacing method and rate
Batching by Volume ASTM C685 Yi ld h kYield checks Proportioning checks Tolerances for batching by volume: Cement, mass% 0 - 4 Fi %Fine aggregate, mass% 2 Coarse aggregate, mass% 2 Admixturesmassorvolume% Admixtures, mass or volume
Transporting and Storing Pesticides Safely Transporting Pesticides Every pesticide applicator should understand the hazards of transporting pesticides and the procedures for minimizing those risks. Pesticides are moved by manufacturers to distributors, from retailers to end users, and from storage sites to job sites. Transportation-related
ACI 304R-00, Guide for Measuring, Mixing, Transporting, and Placing Concrete (Reapproved 2009) ACI 311.4R-05, Guide for Concrete Inspection ACI 311.5-04, Guide for Concrete Plant Inspection and Testing of Ready-Mixed Concrete ACI 347-04, Guide to Formwork for Concrete ACI 207.1R-05, Guide to Mass Concrete (Reapproved 2012)
on cattle when loading, unloading, or transporting animals. Handle/transport all cattle in a manner to minimize stress, injury, and bruising. When transporting cattle, use vehicles that provide for the safety of . personnel and cattle during the loading, transporting, and unloading . processes. Follow these guidelines when transporting livestock:
2. American Concrete Institute (ACI) 304R-00, "Guide for Measuring, Mixing, Transporting, and Placing Concrete" 3. American Concrete Institute (ACI) 308.1-98, "Standard Specification for Curing Concrete" 4. ASTM A185-02, "Steel Welded Wire Fabric, Plain, for Concrete Reinforcement" 5. ASTM C33-03, "Concrete Aggregates" 6. ASTM C94-03, "Ready .
Concrete Beams 9 Lecture 21 Elements of Architectural Structures ARCH 614 S2007abn Reinforced Concrete - stress/strain Concrete Beams 10 Lecture 21 Elements of Architectural Structures ARCH 614 S2007abn Reinforced Concrete Analysis for stress calculations steel is transformed to concrete concrete is in compression above n.a. and
Redi-Mix Concrete, LLC 10K11521 . While EPDs can be used to compare concrete mixtures, the data cannot be used to compare between construction products or concrete mixtures used in different concrete products unless the data is integrated into a comprehensive LCA. For example, precast concrete, concrete masonry units and site cast concrete all .
Overall, instead of transporting the abstract and unob-served Uin the original transportability theory of Eq. (1), we transport the concrete and learnable disentangled causal mechanisms, which generate the observed proxy of U. Therefore, we term the approach as Transporting Casual Mechanisms (TCM) for UDA. Through extensive experi-
The concrete on the top crushes before the steel yields (brittle) The steel yields before concrete crushes (ductile) The concrete will fail in compression at a concrete strain of 0.003-0.004. The steel will yield at a steel strain of fy/Es or a steel stress of fy. N A ccr h b d nAS Concrete Beam 26 jkm Cracking of the Concrete in Tension
