Design and performance of crack-free environmentally friendly concrete “crack-free eco-crete”.

Details

• Creators:
  Khayat, Kamal H. ; Mehdipour, Iman
• Corporate Creators:
  Missouri University of Science and Technology. Center for Transportation Infrastructure and Safety
• Corporate Contributors:
  United States. Department of Transportation. Research and Innovative Technology Administration
• Subject/TRT Terms:
  • Self compacting concrete
  • Environmental impacts
  • Shrinkage
  • Mix design
  • Compressive strength
  • Fly ash
  • Silica fume
  • Slag
  • Binder content
• Publication/ Report Number:
  NUTC R322;Project #00040518
• Resource Type:
  Tech Report
• Geographical Coverage:
  Missouri
• Corporate Publisher:
  Missouri University of Science and Technology. Center for Transportation Infrastructure and Safety
• Abstract:
  High-performance concrete (HPC) is characterized by high content of cement and supplementary cementitious materials (SCMs). ; Using high binder content, low water-to-cementitious material ratio (w/cm), and various chemical admixtures in the HPC can result in ; higher material cost and greater risk of thermal and shrinkage cracking, thus reducing service life of the structure. This project seeks to ; investigate the feasibility of producing crack-free and environmentally friendly concrete (crack-free and Eco-Crete) for building and ; transportation infrastructure applications. Two types of concrete materials, including Eco-super workable concrete (Eco-SWC) and ; Eco-self-consolidating concrete (Eco-SCC) are of special interest in this project. Eco-Crete mixtures are developed with a binder ; content lower than 315 kg/m3 (530 lb/yd3). The concrete should develop 56-day compressive strength greater than 30 MPa (>4350 ; psi). Given the low binder content compared to the targeted performance level, binder composition and aggregate proportion are ; optimized based on the packing density to reduce the voids between particles. The optimized concretes exhibit low shrinkage given ; the low paste content and use of shrinkage mitigation approach, such as the use of a shrinkage reducing admixture (SRA), a Type G or ; K expansive agent (EX), and a lightweight sand (LWS), as well as using fibers to reduce cracking. A factorial design approach was ; also employed to quantify the effect of such materials on mechanical and shrinkage properties. The results indicate that, the combined ; use of 10% silica fume with either 40% fly ash or 40% slag exhibited the highest packing density of 0.66 compared to 0.52 for cement ; paste. The modified Andreasen packing model with distribution modulus (q) of about 0.29 fits reasonable well to express the particle ; size distribution (PSD) of aggregate for SCC with low binder content. Binary shrinkage reducing materials containing 7.5% Type G ; EX and 20% LWS or ternary system including 12.5% Type K EX, 2% SRA, and 20% LWS can be quite effective for developing Eco-Crete mixtures to exhibit crack-free properties.
  More +
• Format:
  PDF
• Funding:
  DTRT06-G-0014
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/27956/dot_27956_DS1.pdf
• File Type:
  [PDF - 5.60 MB]
• Collection(s):
  University Transportation Centers ; US Transportation Collection
• Main Document Checksum:
  urn:sha-512:cf3990df674a2688731f70b17a5345f5adb39e6146da5397412780fc7482b37aa417a1ea4cd177586fb53b11566aadc0bf8fead29f89c008a99e7702435d0c44