Mi\u00f0vikudaginn 3. n\u00f3vember s.l. var haldin kynning hj\u00e1 BM Vall\u00e1.\u00a0\u00c1 kynningunni fjalla\u00f0i Stephan H. Steffen framkv\u00e6mdastj\u00f3ri SF-Kooperation \u00ed \u00de\u00fdskalandi um \u00fdmsar ranns\u00f3knir og n\u00fdjungar \u00e1 steyptum hellum og undirlagi\/bur\u00f0arlagi hellna. Margir kannast vi\u00f0 svo kalla\u00f0a S-steina sem miki\u00f0 hafa veri\u00f0 nota\u00f0ir \u00e1 sv\u00e6\u00f0um \u00fear sem \u00e1lag er miki\u00f0. S-steinar hafa veri\u00f0 framleiddir fr\u00e1 1955.<\/p>\n
Stephan undra\u00f0ist mj\u00f6g hversu f\u00e1ar g\u00f6tur eru hellulag\u00f0ar \u00ed Reykjav\u00edk, t.d. \u00ed mi\u00f0b\u00e6num. \u00cd \u00fev\u00ed sambandi m\u00e1 nefna a\u00f0 hlutfall hellulagna er mun h\u00e6rra en malbiks \u00ed \u00de\u00fdskalandi enda hafi hellur mun meiri styrk og lengri endingart\u00edma.<\/p>\n
Fjalla\u00f0 var um gegndr\u00e6par hellulagnir sem hleypa h\u00e1u hlutfalli yfirbor\u00f0svatns \u00ed gegnum sig. Ger\u00f0ar eru miklar kr\u00f6fur um sj\u00e1lfb\u00e6rar ofanvatnslausnir \u00ed flestum l\u00f6ndum vestur-Evr\u00f3pu (e. Rainwater management).<\/p>\n
Stephan fjalla\u00f0i um \u00fdmsar \u00fer\u00f3anir \u00ed hellul\u00f6gnum, m.a. hellur me\u00f0 sj\u00e1lfhreinsandi yfirbor\u00f0i, hellur me\u00f0 hitav\u00f6rn, hellur sem mosi vex ekki \u00e1 og hellur sem eru s\u00e9rstaklega hugsa\u00f0ar fyrir sl\u00e9tt yfirbor\u00f0 t.d. \u00fear sem fatla\u00f0ir \u00feurfa a\u00f0 komast um.<\/p>\n