Poly (vinyl alcohol) fiber reinforced concrete: investigation of strain rate dependent interphase behavior with single fiber pullout test under quasi-static and high rate loading

• Published in: Journal of adhesion science and technology Vol. 27; no. 4; pp. 385 - 402
• Main Authors: Scheffler, Christina, Zhandarov, Serge, Jenschke, Wolfgang, Mäder, Edith
• Format: Journal Article
• Language: English
• Published: Abingdon Routledge 01.02.2013; Taylor & Francis
• Subjects: Applied sciences; Buildings. Public works; concrete matrix; Concretes. Mortars. Grouts; Exact sciences and technology; failure criterion; fiber/matrix bond; Fibers and threads; Fibre reinforced concrete (including asbestos cement); Forms of application and semi-finished materials; impact behavior; interfacial strength; Materials; Polymer industry, paints, wood; pullout test; PVA fiber; Technology of polymers; failure criterion; PVA fiber; Adhesivity; fiber/matrix bond; interfacial strength; Synthetic fiber; Mechanical properties; Shear strength; impact behavior; Fracture criterion; Experimental study; Modeling; Polyvinylalcohol; Pull out test; Interface properties; Matrix fiber interface; Impact strength; pullout test; Fiber reinforced concrete; Activation energy; concrete matrix
• ISSN: 0169-4243; 1568-5616
• DOI: 10.1080/01694243.2012.705543

A new single fiber pullout device was used to investigate interfacial debonding in the poly (vinyl alcohol) (PVA) fiber-cementitious matrix system under impact loading. For comparison, PVA fibers with two different surface states were used - as-received and after fiber finish removal by extraction in solvents. The indirect method was employed to determine the interfacial strength parameters, namely, the local interfacial shear strength, , and the critical energy release rate, G ic , from the peak load values reached in the pullout test. For both fiber surface states, the and G ic values for high loading rates appeared to be considerably greater than the corresponding parameters determined by means of a quasi-static pullout test. This can be explained using a model based on Zhurkov's kinetic (thermal fluctuation) theory of the strength of solids, which also enabled to estimate the apparent activation energy for interfacial debonding. Its values (1.3 eV for both as-received and treated fibers) evidenced formation of strong bonds between PVA fiber and the concrete matrix and the identity of debonding mechanisms for both fiber types. Finish removal decreased interfacial adhesion due to smoothing the fiber surface and reducing interfacial mechanical bonding.