STUDY OF A NATURAL RESIN USED AS JOINT FOR THE BRICK MASONRY OF HINDU TEMPLES IN MY SƠN (VIETNAM). L. BINDA (1) , G. ZERBI (2) , P. CONDOLEO (1) , E. MANNUCCI (2) , C. TEDESCHI (1) (1) D.I.S. Politecnico di Milano binda@stru.polimi.it (2) CMIC, Politecnico di Milano, Milan, Italy SUMMARY The authors were involved with the archaeologists of the Fondazioni Lerici, Politecnico of Milan, in the preservation of some Hindu temples in My Sơn, Vietnam. The characterisation of the brick- masonry materials was carried out at the Politecnico of Milan. Particularly interesting also for future developments was the successful study of the natural resin used to bond the bricks in the masonry and the research of new compatible resins to be used for the repair and restoration. The results of the research are presented together with some proposal for future research. INTRODUCTION A team of the DIS- Politecnico of Milano was asked in 2000 by the archaeologists of the Lerici Foundation (Politecnico of Milan) and by the Institute for Conservation of Monuments in Hanoi to visit the My Sơn (Vietnam) archaeological site. The Hindu temples built by the Cham people between the 6th and the 14th cent AD need preservation and repair. A decision was taken by the Italian team to work out a pilot project for the preservation of the so called group G. The attention of the brick masonry of the team was particularly attracted by peculiar technique of construction; in fact the horizontal and vertical bonding between bricks was so tight that they did show a sort of continuity in the wall. Moreover, this bond was still preserved after centuries and no (or very small) biological decay was noticed on the surface of the wall and the decay did not penetrate inside the wall. The binder used between bricks was recognised later by experimental investigation as a natural resin. The most modern techniques of Vibrational Spectroscopy (Infrared and Raman) were used to identify the nature of the material at the molecular level. Strong indications were observed in the spectra that one of the original components of the resin (dipterocarpol) may have suffered along the years by self-oxidation in the presence of atmospheric oxygen. During the various visits it was also realized that a supposedly similar vegetal resin was presently available on the market and used for caulking boats. The analysis was also extended to a glue extracted from some local trees (Daù Raì). Click here to search Click here for table of contents