BALWOIS 2008 - Ohrid, Republic of Macedonia - 27, 31 May 2008 1 DAMS WITH IMPERVIOUS MEMBRANE OF ASPHALT CONCRETE Kusari Laura 1 , Ahmedi Figene 2 1. Msc. of Civil Engineering, University of Prishtina, Technical Faculty, p.n., +381 38 554 899/103, Kosovo, Email: laurakusari@yahoo.com 2. Msc. of Civil Engineering, University of Prishtina, Technical Faculty, p.n., +381 38 554 899/103, Kosovo, Email: figene_ahmedi@yahoo.com ABSTRACT Even though the earth dams have been constructed since the earliest times, it is the increase of our ability to build safer and economical structures, which makes those dams even more acceptable. The earth dams can be constructed with impervious membranes of manufactured materials such as concrete, steel and asphalt concrete. These dams are safer against shear failure than any other type of earth or rock fill dam. Consequently, for a given safety factor, the embankment slopes can be made steeper and the embankment volume smaller. Also they tend to be less costly and more easily and rapidly build up than the dams with earth core. In this paper, the focus is given on construction of impervious asphalt concrete membrane as well as some of its general advantages and disadvantages. Also, the circumstances favoring the use of upstream asphalt concrete membranes are given, in order to make easier the decision whether it can be used or not. Special attention is paid to the critical connection details, at the interfaces of membrane-plinth-cutoff. So, it can be concluded that dams with impervious membrane of asphalt concrete are concurrent to other types of dams, because of their easy and fast construction, and their lower costs. If the design and construction of those dams is based on favoring circumstances, than the dams with impervious membranes are acceptable and sustainable. KEY WORDS Bituminous concrete membranes, layers, plinth, dams. INTRODUCTION A bituminous concrete membrane as a water barrier for a dam is a competitive and cost-wise solution then the other conventional designs, like an earth core or other alternatives. According to the 32 nd bulletin of International Committee on Large Dams (ICOLD), there are about 332 dams constructed with bituminous concrete upstream membrane all over the world. Only in Italy, starting from the early 1959 there are 38 dams constructed with bituminous membrane. According to the same sources, the recent dams with bituminous concrete membrane completed in Italy are: Menta Dam (1997), 90 m high and Chiauci Dam (1997), 78 m high. If compared the time of construction of these kinds of world’s dams with their height, we can see that there are great achievements as the height of dams is increasing every year. Bituminous concrete membranes are frequently used as water barriers on the upstream face of dams, thanks to some of their advantages. As early as 1300 BC, in Mesopotamia, according to Baron Van Asbeck, the oldest known dam Assur, was constructed with a kind of primitive bituminous concrete membrane. It is of a great importance, because it gives testimony of the antiquity of the design concept.