Title: High Performance Concrete in Florida Bridges

Author(s): J. Armaghani, D. Romano, M. Bergin, and J. Moxley

Publication: Symposium Paper

Volume: 140

Issue:

Appears on pages(s): 1-24

Keywords: admixtures; bridges (structures); compressive strength; cores; durability; field tests; high performance concretes; mix proportioning; models; permeability; strength; tests; Materials Research

DOI: 10.14359/3904

Date: 9/1/1993

Abstract:
A high performance concrete (HPC) mixture was developed in the laboratory and later used in a bridge construction project. The HPC mixture was designed based on 752 lb (341 kg) of cement with 0.33 water-cement ratio. The weight of the cement was partially replaced by fly ash (20 percent) and silica fume (8 percent). The concrete mixture incorporated 4.5 gal./yd 3 (22.3 L/m 3) of calcium nitrite corrosion inhibiting admixture. Other chemical admixtures included air-entraining agent, and/or standard and high range water-reducing/retarding admixtures. A wide range of field and laboratory tests were performed on fabricated concrete specimens, as well as on cores from field models and newly cast bridge members. The main tests included field and laboratory testing of permeability, and compressive strength. Results of tests on laboratory and field concrete were very close. The chloride permeability AASHTO T277) of the HPC was very low, ranging between 618 to 1055 coulombs. The compressive strength was high, ranging between 8600 to 10,670 psi (59 to 74 MPa). This study shows that laboratory produced HPC with multiple cementitious materials and chemical admixtures can be successfully implemented in construction without compromising its durability. It is also demonstrated that sacrificial concrete models cast and cured at the job site can provide accurate evaluation of the durability and performance of newly cast structures. The study also emphasizes the need to test the permeability as well as strength for more precise assessment of concrete durability.