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Rehabilitation of asphalt concrete layers of road pavements using HIR technologies enables effective elimination of surface defects (rutting, cracking, raveling, bleeding (flushing)) including defects caused by the non-conformity of asphalt concrete to the standard specifications. Due to the economical and ecological advantages, HIR technologies belong to the present-day effective alternative methods of rehabilitation of asphalt concrete pavements. In Ukraine, HIR technologies were first applied on intermediate repair works on an area of the international road I-01 “Kyiv-Chernihiv-Novyye Yarylovichi” in the 2013. Now, HIR technologies have been applied on repair works on numerical objects including areas on such state motor roads as I-01, I-06, N-09, R-10, R-67. The presented paper analyzes the results of monitoring of materials and technologies which was aimed on HIR performance investigation supported by State Road Agency of Ukraine (Ukravtodor) throughout 2014-2018. The results of monitoring of HIR technologies including laboratory evaluation of materials and also field testing of the rehabilitated pavements led to the conclusions fitted by the world-wide experience on implementation of HIR technologies. 1. Being applied to the structurally sound pavements, HIR provides effective elimination of surface defects of flexible pavement to a depth of (50-60) mm including defects caused by the non-conformity of asphalt concrete to the standard specifications. However, HIR is not suitable for existing asphalt pavements which have too much variation in asphalt concrete composition and thickness within the project limits. 2. The efficiency of asphalt pavement rehabilitation using HIR technologies largely depends on precise engineering consideration which determines the efficiency of preparatory (repair) works including some special works such as: – correction of cracks in case of cracking that extends below the depth of hot recycling; – re-compaction of an unbound base layer(s) in case of the insufficient compaction causing “alligatored” network-like cracking of asphalt pavement. 3. Proper technical and working conditions of the rehabilitated pavement during the nominal life cycle could be maintained by overlaying the surface treatment using bituminous emulsion materials or by single-pass overlaying a new hot-mixed asphalt concrete layer. Investigations accomplished during the implementation of HIR technologies allow enhance quality of recycled materials and also promote the entire adaptation of HIR technologies to the Ukrainian standards. Keywords: asphalt pavement rehabilitation, hot in-place recycling, recycled asphalt concrete, field testing, road pavement strength measurement, rutting measurement.

Ɇɚɬɟɣɱɢɤ ȼ.ɉ., ɞɨɤɬɨɪ ɬɟɯɧɿɱɧɢɯ ɧɚɭɤ ɇɚɰɿɨɧɚɥɶɧɢɣ ɬɪɚɧɫɩɨɪɬɧɢɣ ɭɧɿɜɟɪɫɢɬɟɬ Ʉɢʀɜ ɍɤɪɚʀɧɚ ZPDWH#XNUQHW RUFLGRUJ Ʌɚɜɪɨɜ Ɉ.Ⱥ., ɞɨɤɬɨɪ ɬɟɯɧɿɱɧɢɯ ɧɚɭɤ ɍɧɿɜɟɪɫɢɬɟɬ ɩɪɢɤɥɚɞɧɢɯ ɧɚɭɤ Ʉɚɣɡɟɪɫɥɚɭɬɟɪɧ ɇɿɦɟɱɱɢɧɚ DOH[DQGHUODYURY#KVNOGH ɇɚɝɚɣɱɭɤ ȼ.Ɇ ɤɚɧɞɢɞɚɬ ɬɟɯɧɿɱɧɢɯ ɧɚɭɤ Ⱦɉ ȾȿɊɀȾɈɊɇȾȱ Ʉɢʀɜ ɍɤɪɚʀɧɚ QYP#GRUQGLRUJXD KWWSVRUFLGRUJ Ʉɨɦɚɪ Ʉ.ȼ., ɇɚɰɿɨɧɚɥɶɧɢɣ ɬɪɚɧɫɩɨɪɬɧɢɣ ɭɧɿɜɟɪɫɢɬɟɬ Ʉɢʀɜ ɍɤɪɚʀɧɚ NDW\DNRPDU#JPDLOFRP RUFLGRUJ

Introduction.Road pavement is one of the most material-intensive and expensive elements of the road. The quality and durability of the road as a whole depend on the type of road construction material and the method of its application. Considering the significant needs of the road industry in construction materials, there is a need to find effective materials, the use of which allows building the road pavement that can resist the loadings of modern vehicles during the standard service life of pavement. In order to minimize the cost of construction and the negative impact on the environment, it is advisable to use local stone materials, the use of which allows obtaining the efficient road structures on their basis, requires minimal transportation costs and contributes to environmental protection.Problem statement. On the territory of Ukraine there are many deposits of stone materials and products of their associated processing in the form of crushing screenings [1–5]. These materials can be used as the stone materials for pavement layers arrangement without reinforcing binders, also for improving of their properties by strengthening with various types of binders.For strengthening and improving the properties of stone materials can be used the following:–inorganic binders, which include cement, lime and slag alkaline binder;organic binders, which include bitumen, bituminous emulsions and foamed bitumen–complex binders in the form of combination of cement with bitumen, as well as cement with bitumen emulsion or foamed bitumen.Considering the growth of transport loadings on road structures, it is necessary to provide the use of reliable and durable structures, for the construction of which it can be used available domestic raw materials. Organic binders, which include bitumen imported to Ukraine, are quite expensive and their cost is constantly rising. One of the perspective ways for solving this problem is the use of slag alkaline binders and concretes on their basis in the road construction, using local stone materials of different genesis as aggregates.Purpose. The purpose is to study the possibility of obtaining effective slag alkaline concrete with use as a mineral aggregate the stone materials of different mineralogical composition and strength, suitable for non-rigid pavement layers arrangement, capable to operate under repeated short-term loadings.Materials and methods. The erupted and sedimentary rocks that most widespread in Ukraine were used for study, namely: organic-hemogenic limestones, quartzite-like sandstones and granite materials. Blast furnace granulated slag and soda alkali flux were used as binder components. The mechanical properties and physical and chemical processes that occurred during the slag alkaline hardening were studied, and the technological parameters and the features of preparation of such concretes were studied. The state of the contact zone between the slag alkaline stone binder and various aggregates was determined by a set of methods allowed studding the physical and mechanical characteristics of the contact zone (micro hardness) and determining the distribution of the concentration of basic chemical elements in the contact zone, the composition of new formations and its microstructure.Results. The possibility of obtaining of effective slag alkaline concrete on aggregates of different mineralogical composition and strength that are suitable for non-rigid pavement layers arrangement that are capable for operating under repeated cyclic loadings, was theoretically determined and experimentally confirmed.Keywords: slag alkaline concrete, limestone, granite, sandstone, blast furnace milled granulated

The hot in-place recycling (HIR) belongs to the successful strategies of asphalt concrete pavements rehabilitation that provides effective elimination of such surface defects as cracking, rutting, stripping, raveling, and bleeding including defects caused by the non-conformity of asphalt concrete to the standard specifications. The HIR technologies are divided into four methods: «Reshape», «Repave», «Remix», and «Remix Plus». Among those methods, «Remix» and «Remix Plus» are more complicated technologically and are connected with changing the composition of existed (old) asphalt concrete. The composition of existed asphalt concrete should be corrected through the addition some of new components (aggregates, asphalt binder, rejuvenating agent, or new hot-mixed asphalt concrete mixture) to the hot-milled old asphalt layer. This article is dedicated to the methods of calculation of new and recycled aggregate mixture gradation regarding to the Ukrainian standards. The proposed methods of calculation consider such main peculiarities of HIR-recycled materials and layer design as: 1) old asphalt concrete, particularly its aggregate parts, can used in a non-fractioned form only; 2) HIR-recycled asphalt concrete layer should be designed with or without the maximal layer thickness restriction. The proposed methods also give the possibility to correct the technological process if the calculated amount of new material necessitated to the correction of old asphalt concrete aggregate grading does not allow to maintain the projected layer thickness. The implementation of the proposed technique of calculation of aggregate grading with and without restriction of the maximal thickness of recycled asphalt concrete layer allows enhance quality of recycled materials and promotes the entire adaptation of HIR technologies to the Ukrainian standards. Keywords: hot in-place recycling of asphalt concrete, «Remix», «Remix Plus», recycled asphalt concrete mixture, correction of aggregate gradation.