Abstract
Low modulus polymeric yarns (fibers) can be used as primary reinforcement in thin sheet cement products if their bonding to the matrix can be made sufficiently high. Straight yarns usually have a low bond due to the hydrophilic nature of the yarn and its low modulus which does not allow for sufficient clamping stresses to develop and enable effective frictional bond. In the present paper the potential of modifying the shape of the yarn to achieve a crimped geometry was studied to enhance its bond resistance. Such geometry can be achieved in the production of individual yarns and it is the geometry which exists in woven fabrics. The crimped yarns investigated here were obtained by untying yarns from woven fabrics. The fabrics were produced especially for this work to achieve controlled geometry of the yarn, which was characterized in terms of the wave length and amplitude of the crimped shape. The bonding performance was characterized by pull-out tests of the crimped yarns. The crimped shape enhanced the bonding considerably, and the pull out resistance was found to be a linear function of the product of the wave amplitude of each crimp and the number of waves (i.e., yarn length/wave length) along the yam. The dominant bonding mechanism was mechanical anchoring.
| Original language | English |
|---|---|
| Pages (from-to) | 1099-1111 |
| Number of pages | 13 |
| Journal | Cement and Concrete Research |
| Volume | 27 |
| Issue number | 7 |
| DOIs | |
| State | Published - 1 Jan 1997 |
| Externally published | Yes |
ASJC Scopus subject areas
- Building and Construction
- General Materials Science