Andrzej Głuchowski

Environmental and Geotechnical Assessment of the Steel Slags as a Material for Road Structure

Slags are the final solid wastes from the steel industry. Their production from waste and associated materials is a proper implementation of the basic objectives and principles of the waste management. This study aims to investigate the chemical and selected significant geotechnical parameters of steel slag as the alternative materials used in road construction. These investigations are strongly desired for successful application in engineering. Young’s modules E, and resilient modules Mr showed that their values corresponding with requirements for subbase (principal or auxiliary) and riding surface as well. Tested mechanical properties were conducted in soaked and un-soaked (optimal moisture content) conditions. The designated high content of chromium and zinc are strongly associated with the internal crystal structure of steel slag. The results do not lead to threats when they are applied in roads’ structures. Mechanical characterization was obtained by performing California bearing ratio (CBR) tests for steel slag in fixed compaction and moisture content conditions. Moreover, cyclic loading of steel slag was conducted with the application of cyclic California bearing ratio (cCBR) apparatus to characterization of this material as a controlled low-strength material. Finally, field studies that consist of static load plate VSS tests were presented.

Deformation Behavior of Recycled Concrete Aggregate during Cyclic and Dynamic Loading Laboratory Tests

Recycled concrete aggregate (RCA) is a relatively new construction material, whose applications can replace natural aggregates. To do so, extensive studies on its mechanical behavior and deformation characteristics are still necessary. RCA is currently used as a subbase material in the construction of roads, which are subject to high settlements due to traffic loading. The deformation characteristics of RCA must, therefore, be established to find the possible fatigue and damage behavior for this new material. In this article, a series of triaxial cyclic loading and resonant column tests is used to characterize fatigue in RCA as a function of applied deviator stress after long-term cyclic loading. A description of the shakedown phenomenon occurring in the RCA and calculations of its resilient modulus (Mr) as a function of fatigue are also presented. Test result analysis with the stress-life method on the Wohler S-N diagram shows the RCA behavior in accordance with the Basquin law.

Determination of the Resilient modulus MR for the lime stabilized clay obtained from the repeated loading CBR tests

Abstract Determination of the Resilient modulusMR for the lime stabilized clay obtained from therepeated loading CBR tests. The main aim of this paper is to prove that CBR repeated test is useful to give an adequate like unconfi ned cyclic triaxial test parameters for design the pavement and subgrade soils. That parameter is the Resilient modulus (MR) which is the elastic modulus based on the recoverable strain under repeated load. Resilient modulus (MR), is an important parameter which characterizes the subgrade’s ability to withstand repetitive stresses under traffic loadings. The 1993 AASHTO guide for design of flexible pavements recommends the use of MR. The additional aim is connected with the concept of sustainable development. For many countries, where resources are at premium, it is very important that stabilized local soil can be used for road construction. For ensuring that stabilized clay can be used for pavement material standard compaction, CBR and repeated CBR tests were performed. In that paper parameter MRof the subgrade lime stabilized clay soil by laboratory CBR repeated test were determined using for calculation formulas from triaxial cyclic test. Based on AASHTO empirical equation the static CBR values using back analysis was also calculated. Finally both values of CBR determined and calculated were compared. Streszczenie Wyznaczanie modułu sprężystościMR w warunkach cyklicznego obciążania z badańpowtarzalnego CBR dla glin stabilizowanychwapnem. Głównym celem niniejszej pracy jest wykazanie, że badanie CBR w warunkach powtarzalnego obciążania jest wiarygodnym testem do wyznaczania parametrów sprężystości podłoża gruntowego. Parametry te są następnie wykorzystywane do projektowania podbudowy i ulepszonego podłoża gruntowego. Jednym z parametrów jest powtarzalny moduł sprężystości (MR) który opisuje odkształcenia sprężyste powstałe w wyniku cyklicznych obciążeń gruntu. Powtarzalny moduł sprężystości MR, jest ważnym parametrem, który charakteryzuje zdolność podbudowy do odkształceń w wyniku powstających naprężeń od obciążenia ruchem drogowym. Podręcznik AASHTO 1993 do projektowania elastycznych nawierzchni zaleca stosowanie MR. Celem artykułu jest także podjęcie problemu zasad zrównoważonego rozwoju. W wielu krajach, w których źródła odpowiednich kruszyw są oddalone od miejsca budowy, bardzo ważnym staje się wykorzystanie materiałów miejscowych poddanych zabiegom stabilizacyjnym. W celu potwierdzenia korzystnego wpływu stabilizacji na grunty spoiste o niekorzystnych parametrach wyjściowych wykonano badania CBR w warunkach statycznego obciążania i powtarzane badania CBR. W artykule wyznaczono parametr MRdla gliny piaszczystej stabilizowanej wapnem hydratyzowanym za pomocą badania powtarzalnego CBR przy zastosowaniu równań opracowanych dla interpretacji badań trójosiowego ściskania w warunkach cyklicznego obciążenia. Na podstawie równania empirycznego AASHTO wyznaczono również wartości CBR a także wykorzystano analizę wsteczną wyznaczenia wartości CBR z otrzymanych z badań wartości MR. W analizie wyników badań wartości te zostały ze sobą porównane wraz z komentarzem uzyskanych zależności.

Impact of the stabilization of compacted cohesive soil – sandy clay on yield criterion improvement

Abstract Impact of the stabilization of compacted cohesive soil - sandy clay on yield criterion improvement. Soft soils, exhibiting low strength properties in the case of external load, require improvement. Chemical stabilization is easy in preparing and presents very good results in improving mechanical properties. In this paper, results of CBR and unconfined compressive strength test are presented for cohesive soil - sandy clay. Stabilization medium was Reymix, which is a cement derivative. Conducted tests define the characteristics of mechanical properties improvement and estimate yield criterion for stabilized soil during the time of stabilization, which is different for non-stabilized soils Streszczenie Wpływ stabilizacji zagęszczonego gruntu spoistego - iłu piaszczystego na wzrost granicy sprężystości. Grunty słabe, które przejawiają niewielką wytrzymałość mechaniczną na obciążenia zewnętrzne, wymagają wzmocnienia. Stabilizacja chemiczna jest łatwa w wykonaniu i daje bardzo dobre wyniki wzrostu właściwości mechanicznych. W artykule przedstawiono wyniki badania CBR oraz jednoosiowego ściskania gruntu spoistego - iłu piaszczystego ulepszonego za pomocą preparatu Reymix, który jest pochodną cementu. Przeprowadzone badania miały na celu określenie charakterystyki poprawy właściwości mechanicznych oraz wyznaczenie dla stabilizowanego gruntu granicy sprężystości, która jest inna niż w przypadku gruntów niestabilizowanych

Effects of stabilization with cement on mechanical properties of cohesive soil – sandy-silty clay

Abstract Effects of stabilization with cement on mechanical properties of cohesive soil - sandy- -silty clay. Ground improvement as a result of stabilization with cement has its impact on soft soils such as sandy clay in engineering constructions. Stabilized soils are also used in foundation design, where improvement of mechanical properties is needed. Because of these reasons, knowledge of physical and mechanical properties is needed. The relationship stress - strain of soils stabilized with cement is often unclear and strength characteristics need to be clear. In this paper results of physical and mechanical properties soil stabilized with cement are presented

Repeated Loading of Cohesive Soil – Shakedown Theory in Undrained Conditions

Abstract The development of industry and application of new production techniques could bring about extraordinary problems that have been neglected. One of these challenges in terms of soil mechanics is high frequency cyclic loading. Well constructed foundation may reduce this troublesome phenomenon but excluding it is usually uneconomic. In this paper, shakedown theory assumptions were studied. Cyclically loaded soils behave in various ways depending on the applied stress rate. Common cohesive soils in Poland, i.e., sandy-silty clays are problematic and understanding of their behaviour in various conditions is desired. In order to study repeated loading of this material, cyclic triaxial test were carried out. Cyclic loading tests were conducted also in one way compression. These methods in small strain regime allow permanent strain increment analysis with resilient response after numerous cycles. This behaviour was subsequently exploited in the study of shakedown theory. This paper contains some conclusions concerning the above-mentioned theory.

Energy-based analysis of permanent strain behaviour of cohesive soil under cyclic loading

In this paper the original results of uniaxial cyclic compression test on cohesive soil are presented. The shakedown phenomena in cohesive soil are described. Energy-based method highlights the change of soil material behaviour from plastic shakedown through plastic creep shakedown to incremental collapse. The samples were cyclically loaded under undrained conditions with the constant amplitude of stress in one-way test procedure. In this study the energy-based method was presented as a proper method to categorise response of cohesive soil to cyclic loading in uniaxial conditions. A shakedown criterion factor, SE, was introduced to help understand the shakedown phenomena in cohesive soil. In cohesive soils the absence of a limit between plastic shakedown and plastic creep shakedown was pointed out.

Estimation of physical and mechanical properties of cohesive soil stabilized by hydratized lime addition

Abstract Estimation of physical and mechanical properties of cohesive soil stabilized by hydratized lime addition. Process of chemical stabilization of cohesive soils influences its mechanical properties, also in the case of soil cohesion. Road constructions consist of few layers which have various mechanical properties and this creates the need for better understanding the impact of chemical stabilization on soil as a layer of road. For the purposes of this article, tests were carried out in order to establish physical and mechanical properties, especially the penetrating resistance CBR test. The main aim of this paper was to estimate the cohesion of the soil, which was sandy-silty clay stabilized with hydrated lime

Estimation of mechanical properties of soil stabilized by hydratized lime addition

Abstract Estimation of mechanical properties of soil stabilized by hydratized lime addition. Design of road pavement is connected with estimation of mechanical properties of each of the materials used for construction. This statement presents the need of estimating the mechanical moduli. For the purposes of this article, tests were carried out in order to establish physical and mechanical properties, especially penetrating resistance CBR. The main aim of this paper was to estimate the optimal lime and water content in soil - clayey sand. The paper presents the expected cyclic behavior of clayey sand, as well as method for calculating the resilient modulus (Mr). Streszczenie Określenie właściwości mechanicznych gruntu stabilizowanego wapnem hydratyzowanym. Projektowanie konstrukcji drogowych wiąże się z określeniem właściwości mechanicznych każdego materiału użytego do konstrukcji drogi. Oznacza to potrzebę wyznaczenia charakterystycznych wartości modułów wytrzymałościowych. W artykule podjęto badania mające na celu określenie właściwości fizycznych i mechanicznych gruntu. Wykonano badania wytrzymałościowe i badania nośności CBR gruntu. Celem badań było określenie na tej podstawie optymalnej zawartości wapna i wody w mieszance z gruntem naturalnym - piaskiem gliniastym. W artykule przedstawiono także przewidywane zachowanie się gruntu w wyniku obciążeń cyklicznych oraz obliczenia cyklicznego modułu sprężystości (MR).

Studies on resilient modulus value from cyclic loading tests for cohesive soil

Abstract In this article the cyclic CBR test as a reference method in determination of resilient modulus (Mr) is confronted with results of cyclic triaxial and unconfined uniaxial cyclic test. The main idea of conducted experiments is establish relationship between cyclic loading tests in testing of natural subsoil and road materials. The article shows results of investigation on cohesive soil, namely sandy silty clay, commonly problematic soil in Poland. The results of repeated loading triaxial test resilient modulus were displayed in order to compare them with cyclic CBR test results by using the Mr–Ө model. Some empirical correlation between factors obtained from triaxial test or uniaxial unconfined cyclic test and cyclic CBR test was introduced here. The behavior of resilient modulus was also examined in this paper.