Large-Scale Processing of Engineered Cementitious Composites
The design, processing, and evaluation of engineered cementitious composites (ECC) is investigated at large scales, up to 3 m3 (4 yd3). The design of ECC is undertaken to retain the pseudo-tensile strain-hardening properties characteristic of high-performance fiber-reinforced cementitious composites (HPFRCC) while optimizing for transit truck mixing procedures and short mixing times. Material design is based on tensile multiple cracking and grain size distribution criterion. Success of this design procedure is demonstrated at both small scales of 200 L (7 ft3) and large scales of 3 m3 (4 yd3). Large-scale mixing specimen material properties are tested to establish a preliminary set of design values based on statistical analysis of large-scale mixing test results. Tests show that design parameters for compressive strength, tensile strength, and tensile strain capacity can be set at 60 MPa (8.75 ksi), 4.35 MPa (630 psi), and 2.0%, respectively, for the ECC-M45 material tested with 99% confidence.