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:
  Binder Content Compressive Strength Environmental Impacts Fly Ash Mix Design Self Compacting Concrete Shrinkage Silica Fume Slag
• 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.
  
  
• Format:
  PDF
• Funding:
  DTRT06-G-0014
• Collection(s):
  University Transportation Centers US Transportation Collection
• Main Document Checksum:
  urn:sha-512:cf3990df674a2688731f70b17a5345f5adb39e6146da5397412780fc7482b37aa417a1ea4cd177586fb53b11566aadc0bf8fead29f89c008a99e7702435d0c44
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/27956/dot_27956_DS1.pdf
• File Type:
  [PDF - 5.60 MB ]