Details:

Corporate Creators:
Missouri University of Science and Technology
Subject/TRT Terms:
[+]
Concrete Construction Fly Ash Pavements--Performance Portland Cement--Additives Reinforced Concrete--Testing Cement Additives Economic Impacts Mix Design Performance Tests Portland Cement Recycled Materials Reinforced Concrete
Publication/ Report Number:
TRyy1110
Resource Type:
Tech Report
Geographical Coverage:
Missouri
Corporate Publisher:
Missouri. Dept. of Transportation
NTL Classification:
NTL-HIGHWAY/ROAD TRANSPORTATION-Pavement Management and PerformanceNTL-HIGHWAY/ROAD TRANSPORTATION-Design
Abstract:
In the Paste Screening Study, 25 combinations of five Type I/II portland cements

and five Class C fly ashes commonly used in Missouri were tested in paste form with no

chemical or powder additives. Testing procedures included semi-adiabatic calorimetry,

Vicat setting time, miniature slump, and compressive strength at one and 28 days. The

two most reactive and two least reactive combinations (defined by one day strengths)

were further evaluated in the Paste Main Effects Study. Eighty mixtures were examined.

In the Paste Main Effects Study, the effects of two levels each of WR/HRWR,

gypsum, calcium hydroxide (lime), rapid set cement (RSC), and gypsum-lime, and

gypsum-RSC were determined. Except for the WR/HRWR dosage level experiment, all

other mixtures contained a low WR/HRWR dosage. Except for the gypsum level

experiment, all other mixtures contained 4% gypsum. The lime levels were 5 and 10%

and the RSC levels were 10 and 20%. All percentages are by mass of fly ash. Sixty-four

mixtures were examined.

The objective of the Concrete Properties Study was to scale up from paste to

concrete the most promising powder additive combinations and then evaluate the

mixtures in terms of plastic and hardened properties. Thus the mixture matrix included

ordinary portland cement (OPC)-fly ash blends at two levels (same as in the Paste Main

Effects Study) and fly ash at three levels (zero, 50 and 70%). WR dosage (nominal

dosage), gypsum content (4%), lime content (10%), and RSC content (20%) were held

constant. Ten concrete mixtures were evaluated.

At the 50% fly ash level, one day strengths were low no matter which powder

additives was used, but good strengths were achieved by day 3. At the 70% fly ash level, the concrete was weaker than at zero and 50% fly ash, but reasonable strengths were

reached at 28 days. At 50% fly ash, abrasion resistance was somewhat lower. At 70% the

effect was much worse. In regard to drying shrinkage, it appears that HVFA mixtures

shrink less than their OPC counterparts. In a comparison to OPC mixtures, rapid chloride

permeability (RCP) was lower for 50% fly ash mixtures, but 70% fly ash mixtures are

more permeable. All HVFA mixtures had greater freeze-thaw Durability Factors than the

OPC mixtures, and were at 93 or above. However, all fly ash mixtures did poorly in

regard to salt scaling. Reaction time (calorimeter curve time, setting time, stiffening time)

varied as a function of characteristics of the OPC and fly ash in conjunction with each

other, type and level of powder additives used, dosage of WR/HRWR, and the type of

test method used for evaluation.


Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:20e663b5b86f6667e303c4650dd1f63d6f948026e82c3bd62a689305128ac683
Download URL:
https://rosap.ntl.bts.gov/view/dot/25526/dot_25526_DS1.pdf
File Type:

Supporting Files

• No Additional Files

More +