Specifications - City of Montpelier, Vermont

Montpelier District HeatingCity of Montpelier, VT02520 – Portland Cement Concrete PavingIssue Date:September 28, 2012Page #:5 of 10A. Boiled Linseed Oil Mixture: Combination of boiled linseed oil and mineral spirits,complying with AASHTO M233.2.7 CONCRETE MIXA. Prepare design mixes for each type and strength of normalweight concrete by eitherlaboratory trial batch or field experience methods as specified in ACI 301. For the trialbatch method, use a qualified independent testing agency for preparing and reportingproposed mix designs.1. Do not use the Owner's field qualitycontrol testing agency as the independenttesting agency.2. Limit use of fly ash to 20 percent of cement content by weight.B. Proportion mixes according to ACI 211.1 to provide normalweight concrete with thefollowing properties:1. Compressive Strength (28Day): 4000 psi.2. Maximum WaterCement Ratio at Point of Placement: 0.44.3. Slump Limit at Point of Placement: 24 inches.4. Modulus of Rupture: 650 psiC. Add airentraining admixture at manufacturer's prescribed rate to result in concrete atpoint of placement having an air content as follows with a tolerance of plus or minus 1percent:1. Air Content: 6.0 percent for 1inch maximum aggregate.D. Fiber Reinforcement: Add to mix at rate of 1.5 lb per cu. yd., unless manufacturerrecommends otherwise.2.8 CONCRETE MIXINGA. ReadyMixed Concrete: Comply with requirements and with AASHTO M 157.1. When air temperature is between 85 deg F (30 deg C) and 90 deg F (32 deg C),reduce mixing and delivery time from 11/2 hours to 75 minutes; when airtemperature is above 90 deg F (32 deg C), reduce mixing and delivery time to 60minutes.PART 3EXECUTIONPORTLAND CEMENT CONCRETE PAVING 02520 5