PORTLAND CEMENT CONCRETE PRODUCTION SECTION 1022 661 Slip-formed elements 0.5 to 2.5 Self-consolidating concrete Refer to Section 1022.16 1 Use only Type F or Type G admixtures for slumps greater than 4 -inches. The maximum allowable slump is 8 -inches. 2 Slump may be increased up to 8 -inches if Type F admixture is used.
1022.10 Material Production Requirements.
A.Notify the Department’s Materials and Research Section of the quantity and time of scheduled release by 3:00 PM the non -holiday weekday before production.
1022.11 Handling and Storage of Materials.
A.Aggregates.
1.Stockpile aggregates on hard, clean, surfaces with positive drainage. The surface must be constructed of PCC or bituminous concrete that is of sufficient thickness to support the weight of the stockpile without rupturing or cracking. If the stockpile su rface deteriorates and possibly contaminates aggregate stockpiles, immediately suspend concrete production until the surface is repaired. Maintain suitable partitions to separate and contain fine and coarse aggregate stockpiles. Stockpile coarse aggregate in a manner to avoid segregation.
2.Stockpile fine aggregates at the batch plant for a minimum of 24 -hours or until surplus water has drained and the material has a uniform free moisture content before batching. Do not batch concrete using material directly from the washing plant. Maintain suitable partitions to prevent wet fine aggregates from mixing wit h fine aggregate.
3.Construct haul roads to the concrete plants to prevent any deleterious materials from entering the batching process. If deleterious materials are discovered anywhere in the batching process, immediately suspend operations until these conditions are corr ected.
B.Cementitious materials.
1.Store cementitious materials in suitable structures that protect the material from hydration.
2.Do not use any cementitious material that shows signs of hydration such as lumps or cakes.
C.Admixtures .
1.Store admixtures to prevent contamination, stratifications, or deterioration.
2.Agitate admixtures according to the supplier’s recommendation.
3.When admixture dosage rates differ from the manufacturer’s recommendations, stop production of PCC until the problem is identified and corrected.
1022.12 Production Equipment Requirements.
Meet the requirements of AASHTO M157, except as modified herein:
A.Batch plants.
1.Material Measurement for batching. PORTLAND CEMENT CONCRETE PRODUCTION SECTION 1022 662 a. Weigh individual aggregates to within ±1 percent of the target weight.
b.Weigh combined aggregates to within ±1 percent of the total target aggregate weight.
c.Measure water, by weight or volume, to within ± 1 percent of the required batch quantity of water.
d.Weigh cement to within +1 percent of the target batch weight.
e.Maintain the admixture dispenser accuracy to within ± 1 percent of target volume.
2.Provide a computer printed ticket for each batch issued by the plant to the truck driver. The ticket must contain:
a.The name and location of the plant.
b.The approved mix designation.
c.The size and proportions of the batch.
d.The type and dosage rate of admixtures used.
e.The batch time (determined by the time water is introduced to the mixture).
f.The gallons of water withheld from the mixture that meets the maximum allowable water/cement ratio for the approved mix design.
3.Weighing scales:
a.Scales for weighing material must have a rugged design constructed to support the hopper or belts with minimum adjustments and be consistent with the accuracy required.
b.Scales rated to 5,000 -pounds or less measure in graduations not greater than 5 -pounds.
c.Scales rated greater than 5,000 -pounds measure in graduations not greater than 0.1 percent of the maximum rated load.
d.Maintain scales within a maximum tolerance of 0.5 percent of the net load in the hopper.
e.Retain at least 1 set of the following calibration weights for verifying scale calibrations:
i.10 standard 50 -pound blocks, ii. 11 standard 20 -kg blocks, 1 standard 5 -kg block, and 2 standard 1 -kg blocks, iii. Construct the weights of high quality cast iron and finished in such a manner that foreign materials do not adhere to the surface. iv. The engineer may perform an inspection of these weights.
4.Trucks for batch mix plants:
f.Mix each batch at a rate of rotation specified by the manufacturer more than 70 but less than 100 revolutions.
g.Inspect mixer drums for wear. The Materials and Research Section will verify the condition annually.
h.Keep interior drum surfaces clean of accumulations of hardened concrete material.
i.Replace drum blades when wear exceeds 1 -inch of the original height.
Source: Delaware Standard Specifications for Road and Bridge Construction, 2025 Edition. Pages 671–672 of 779.