Ceļa segu risu veidošanās cēloņu noteikšana

Rīgas ielu pēdējos gados rekonstruēto segu apsekošanā konstatētas izteiktas garenvirziena deformācijas jeb risas. Šādas deformācijas pazemina ceļu satiksmes drošību un ērtību. Šī pētījuma mērķis – noteikt ABS tipa asfaltbetona segumu risveida deformāciju rašanās cēloņus un izstrādāt rekomendācijas to novēršanai. Pētījuma gaitā veikta risu klasifikācija pēc to izcelsmes, izvirzīti iespieduma-izspieduma risu iespējamie rašanas cēloņi, kā arī izplānota eksperimentālā daļa - laboratorijas apstākļos izanalizēt ABS tipa asfaltbetona mehānisko īpašību izmaiņas pie dažādām temperatūrām. Noskaidrots, ka ABS tipa asfaltbetona izgatavošanai izmantotais neuzlabotais (nemodificētais) bitumens neuzrāda pietiekoši viskozas un labas adhēzīvās īpašības pie augstām vasaras temperatūrām. Noskaidrots arī, ka šīs temperatūras pārsniedz bitumena mīksttapšanas temperatūru un laikā sakrīt ar lielāko satiksmes intensitāti pilsētas ielās

Prediction of Rutting Formation in Asphalt Concrete Pavement

Asphalt pavement in actual circumstances is subjected to the repetitive and changing transport load. As a result of the repetitive load impact, both elastic and plastic deformations occur to the pavement. Accumulation of plastic deformations in one or several layers leads to appearance of permanent deformations or rutting. This type of deformations reduces safety and convenience of traffic. Aim of the research is investigation of the rutting dynamics on the dense graded asphalt concrete (AC) and stone mastic asphalt (SMA) mixtures. The research has been made by using the standard performance test method – wheel tracking test (WTT). Five compositions of the dense graded AC mixture and two compositions of the SMA with the conventional aggregate and one reference mixture AC 11 with the Martin steel slag aggregate have been used in the experiment. The B70/100 unmodified bitumen and SBS modified ModBit 80B has been used for the investigated mixtures. The results have shown poor strain stability of the conventional mixtures with unmodified bitumen under the heavy transport load, in comparison with the reference mixture AC 11 and SMA with modified bitumen. The results of investigating the rutting dynamics under the intensive heavy transport load have shown that the allowed rut depth 25 mm is reached already during the first year of the asphalt pavement exploitation

Autoceļu projektēšanas pamatkurss

Projekta sarurs, automobiļa kustības likumsakarības, redzamība, ceļumezgli, autostāvvieta

Analysis of Unconventional Signalized At-Grade Intersections

The article deals with two types of unconventional intersections – the Median U-Turn intersection and the Superstreet intersection. Available published sources of information have been analyzed for information about the characteristics, design and operations of unconventional intersections. A comparison of unconventional and typical intersections has been made to determine the types of intersections which are more preferable in the specific traffic situations in urban areas. In the process of study it has been identified which of the analyzed intersections provide the best level of service and movement efficiency for the current traffic flow distribution and intensit

Road Traffic Safety on Latvia’s Main Rate Roads

Article analysis traffis safety problems on the main rate road network in Latvia

Mileage and Road Traffic Safety Trends in Latvia

Article analysis mileage calculation problems in Latvia