info on exterior insulation/filling material, etc.-1999

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EPS Geofoam 2001,3rd International Conference, Salt Lake City,December 2001 3 The testing frequency is shown in table 1. Fill location Constructed Test samples retrieved Year No.of years after construction National road 159 Flom bridges 1972/73 0 7 12 24 National road 154 Solbotmoan 1975 4 9 21 County road 91 Lenken 1978 6 County road 261anghus 1977 7 National road 610 Sande-Osen 1982 9 Table 1 Testing frequencies of EPS embankments. MATERIAL BEHAVIOUR Material strength According to Norwegian specifications the design compressive strength of EPS blocks have been set to be at least is= 100 kPa when not otherwise specified In actual practice a shipment of blocks may be accepted if the average strength of tested blocks is 6�:100 kPa.The average value for test specimens from one block(6 tests)should be is z 90 kPa and no single tests should show values 6<SO kPa. One major indicator of possible deterioration of blocks with time would be a decrease in the material strength.The strength tests performed on retrieved samples from fills having been in the ground for up to 24 years are shown in figure 4.as a fimction of dry unit density and compressive strength.Bearing in mind the criteria mentioned above for accepting blocks to be placed in a fill,all test results give values of compressive strength above a=100 kPa except for one test. This one test was performed on samples taken from the ' first fill shortly after it was completed in 1972,and is more an indication of variations in material quality of EPS with the production process used at that time.Still ` + F � � the observed value is within the accepted statistical variations in material strength. hE From figure 4 it may also be observed that the majority of tests show values of compressive strength in relation j; to unit density above that of a normal quality material. Although it is of course impossible to make exact u comparisons between material strength at the time of construction and some time afterwards since tests cannot be performed on the same specimen twice,the results Figure 3.Excavation of a 24 years old EPS block indicate clearly that there are no signs of material from the first EPS embankment at Flom bridge deterioration over the total time span of 24 years.If a change tendency is to be noted,this would go towards a slight increase in material strength.If this is the case,such an increase could be explained by a continued chemical reaction leading to material hardening during the first few weeks after production.There is also a tendency that the material strength is slightly higher in the middle of the block than towards the outer sides.Furthermore there is no Long term performance and durability of EPS as a lightweight filling material