Abstract。 This paper contains a short state of the art overview on bituminous plug joints (BEJ) in Switzerland。 Such BEJs are of particular interest because of their noise reduction properties。 BEJs designed for joint movements up to 100mm were investigated in the lab and field as a basis for guidelines by the Swiss Federal Road Office。 Special test procedures including gel permeation chromatography (GPC), testing of adhesion between joint filling material and adjacent pavement, rutting performance testing with model mobile load simulator MMLS3 as well as cold tempera- ture movement capacity testing with a joint movement simulator are presented。 In addition, long- term field performance of standard BEJs for small joint movements and special wide BEJs, some of them containing moving aids for large joint movements, are discussed。 It was found that the tools and requirements elaborated in the Swiss guidelines are suited to reduce the risk of BEJ failure。 It became also apparent that placing technology and climate play a significant role in achieving well performing BEJ for short and large joint movements。76291

Keywords。 Asphalt, bridge, expansion joints, performance, testing。

This work is licensed under the current Creative Commons Attribution-Noncommercial License。

1 Introduction

1。1 Background

Flexible bituminous (or "asphaltic") plug expansion joint systems (BEJ) are used for short concrete bridges with small maximal horizontal total movements in each joint of about 30 mm for more than 20 years and, recently, even for bridges with large joint movements in the order of 100 mm。 As compared to other systems, these plug joints generally have a shorter life cycle of about 10 to 15 yrs but are easy to install, maintain and repair, provided that work is conducted carefully with sound technical know-how and under favorable weather conditions (dry and warm)。

BEJs are mostly used in combination with asphalt bridge deck pavements allowing a smooth driving surface with a positive effect on traffic noise reduction and driving comfort for cars, motor cycles and bikes。 In fact, the potential of noise reduction is one of the main advantages of this type of plug joint for bridges in heavily populated urban areas and in critical places such as exposed bridges in alpine nature reserves and recreational areas。

In the following, a summary of Empa research results regarding lab and in-situ perform- ance testing is presented together with key elements of the framework developed for the assessment of BEJs in Switzerland。 Further details can be found in [1-6]。

1。2 General  performance requirements

BEJs are expected to provide good protection of the concrete bridge structure against cor- rosion from water and de-icing agents。 They are required to be elastically deformable at very cold seasonal temperatures without suffering loss of stability during hot summer months or traffic induced damage (Fig。 1)。 Such damage may result from vertical static or dynamic mechanical loads, vertical vibrations of the bridge and special situations such as replacement or adjustment of bridge bearings。 It may also result from horizontal tire-road interaction in curves and slopes from breaking and acceleration maneuvers as well as ex- ceptional loads during maintenance, such as winter maintenance with snow-ploughs。 Hence, general requirements for BEJ read as follows:

– durable (e。g。 temperature & weather resistant);

– waterproof (protection of concrete structure, de-icing salts);

– resistance against quasi-static horizontal and vertical bridge movements and dynamic traffic loads without: Loss of adhesion in contact surfaces, low temperature and fatigue cracks, loss of stability in summer, loss of friction (safe breaking), rutting and permanent deformation (aquaplaning, ice), raveling and loss of aggregates;