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1

Badania paneli z gruntobetonu i fibrogruntobetonu do wzmacniania nasypów kolejowych

Gut Remigiusz, Duszyński Andrzej, Jasiński Wiktor, Rychlewski Piotr, Sołtysik Robert

Materiały Budowlane

|

2023

|

nr 2

48--51

PL

W artykule przedstawiono prace badawcze będące częścią projektu dotyczącego opracowania technologii DLM do wzmacniania podtorza kolejowego. Technologia polega na wykonaniu w gruncie in situ dwóch ciągłych i równoległych paneli z gruntobetonu, tj. mieszanki gruntu rodzimego, cementu, wody i ewentualnie dodatków. Badano wytrzymałość i odporność na obciążenia cykliczne paneli wykonanych z gruntobetonu oraz gruntobetonu z dodatkiem włókien, tzw. fibrogruntobetonu. Wyniki potwierdzają spełnienie wymagań ustalonych jako kamienie milowe projektu dotyczącego paneli z obu materiałów.

EN

The article presents research works that are part of the project to develop the DLM technology for strengthening the railway subgrade. The technology consists in making two recessed, continuous and parallel panels of soil-concrete, i.e. a mixture of native soil, cement, water and possible additives. The strength and resistance to cyclic loads of panels made of soil concrete without additives and soil concrete with fibers were prepared. The results confirm that the requirements set as project milestones for panels in both materials are met.

2

Applying different soil stabilization mechanisms: a review

Falah Maydah W., Muteb Haitham

Archives of Civil Engineering

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2023

|

Vol. 69, nr 4

339--358

EN

To guarantee a durable pavement construction that only needs a little care, it is crucial to manage problematic soil conditions properly and prepare the foundation. Some organizations remove soils since they have realized they do not function as well as other materials (for example, a state specification dictating that frost susceptible loess could not be present in the frost penetration zone). Nevertheless, there are more advantageous or desirable courses of action than this (e.g., excavation might create a disturbance, plus additional issues of disposal and removal). The subgrade conditions described in the preceding section may be improved by stabilization, offering an alternative solution. It is impossible to overstate the importance of ensuring a homogeneous soil profile in terms of density, moisture content, and textural categorization in the top section of the subgrade. Thru soil sub-cutting or other stabilizing methods, this consistency may be attained. Additionally, stabilization may be utilized to prevent swelling in expansive materials, create a weather-resistant work platform, enhance soil workability, and limit issues with frost heave. Alternative stabilizing techniques will be discussed in this part, and advice for choosing the best technique will be adequately provided. The current review paper aims to identify bridge issues related to soft soil and takes two ways of soft soil stabilization: chemical and mechanical. The finding of both methods show that the compressive strength and settlement have been improved after using waste materials; therefore, using waste materials as a cement replacement is considered one of the expansive utilized methods in most construction applications and bridges of that applications.

3

Application of steel slag in stabilizations of expansive soil: an experimental study

Kabeta Worku Firomsa

Archives of Civil Engineering

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2023

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Vol. 69, nr 1

105--117

EN

This study was carried out to evaluate the effect of steel slag (SS) as a by-product as an additive on the geotechnical properties of expansive soil. A series of laboratory tests were conducted on natural and stabilized soils. Steel slag (SS) was added at a rate of 0, 5, 10, 15, 20, and 25% to the soil. The conducted tests are consistency limits, specific gravity, grain size analysis, modified Proctor compaction, free swell, unconfined compression strength, and California Bearing Ratio. The Atterberg limit test result shows that the liquid limit decreases from 90.8 to 65.2%, the plastic limit decreases from 60.3 to 42.5%, and the plasticity index decreases from 30.5 to 22.7% as the steel slag of 25% was added to expansive soil. With 25% steel slag content, specific gravity increases from 2.67 to 3.05. The free swell value decreased from 104.6 to 58.2%. From the Standard Proctor compaction test, maximum dry density increases from 1.504 to 1.69 g/cm3 and optimum moisture content decreases from 19.77 to 12.01 %. Unconfined compressive strength tests reveal that the addition of steel slag of 25% to expansive soil increases the unconfined compressive strength of the soil from 94.3 to 260.6 kPa. The California Bearing Ratio test also shows that the addition of steel slag by 25% increases the California Bearing ratio value from 3.64 to 6.82%. Hence, steel slag was found to be successfully improving the geotechnical properties of expansive soil.

4

Ultrasonic P- and S-Wave Reflection and CPT Soundings for Measuring Shear Strength in Soil Stabilized by Deep Lime/Cement Columns in Stockholm Norvik Port

Lindh Per, Lemenkova Polina

Archives of Acoustics

|

2023

|

Vol. 48, No. 3

325--346

EN

In this research project, the measurements of the ultrasonic P- and S-waves and seismic cone penetration testing (CPT) were applied to identify subsurface conditions and properties of clayey soil stabilized with lime/cement columns in the Stockholm Norvik Port, Sweden. Applied geophysical methods enabled to identify a connection between the resistance of soil and strength in the stabilized columns. The records of the seismic tests were obtained in the laboratory of Swedish Geotechnical Institute (SGI) through estimated P- and S-wave velocities using techniques of resonance frequency measurement of the stabilized specimens. The CPT profiles were used to evaluate the quality of the lime/cement columns of the reinforced soil by the interpretation of signals. The relationship between the P- and S-waves demonstrated a gain in strength during soil hardening. The quality of soil was evaluated by seismic measurements with aim to achieve sufficient strength of foundations prior to the construction of the infrastructure objects and industrial works. Seismic CPT is an effective method essential to evaluate the correct placement of the CPT inside the column. This work demonstrated the alternative seismic methods supporting the up-hole technology of drilling techniques for practical purpose in civil engineering and geotechnical works.

5

Strength and Durability of Cement Stabilized Expansive Soil Amended with Sugarcane Press Mud

James Jijo, Selvam Akilan Gunaselvi, Annamalai Krishna Khumaar, Marimuthu Vishal, Srinivasan Vishnu Varadhan, Kolamurugan Sooraj

Civil and Environmental Engineering Reports

|

2022

|

Vol. 32, no. 1

138--151

EN

The present investigation delved into the performance of cement stabilized soil amended with sugarcane press mud (PM), an organic waste residue from the sugar industry. An expansive soil was stabilized using 3% and 8% ordinary Portland cement (OPC) and modified with 1%, 3% and 5% PM. Cylindrical samples of dimensions 38 mm diameter and 76 mm height were cast and cured for 7, 14 and 21 days for all combinations considered. After the designated curing periods, the specimens were strained axially until failure to determine the strength of the samples. Samples were also subjected to alternate cycles of wetting and drying and the resistance to loss in weight was determined. The results of the investigation revealed that PM can be considered as a strength accelerator due to enhancement in early strength of the samples at 7 days of curing but beneficial strength gain could not be sustained over extended curing periods considered. However, 1% and 3% PM modified specimens were more resistant to weight loss when compared to pure cement stabilized specimens. Based on the results of the investigation, PM can be considered as a potential auxiliary additive to cement stabilized soil for improving the durability performance of the soil.

6

The development of an ecofriendly binder containing high volume of cement replacement by incorporating two by-product materials for the use in soil stabilization

Jafer Hassnen, Jawad Ibtehaj, Majeed Zaid, Shubbar Ali

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2021

|

Vol. 30, No. 1

62--74

EN

The development of an ecofriendly binder containing high volume of cement replacement by incorporating two waste materials for the use in soil stabilization. This paper investigates the possibility of replacing ordinary Portland cement (OPC) by two waste and by-product materials for the use of a silty clay soil stabilization purpose. The soil was treated by 9.0% OPC where this mixture was used as a reference for all tests. Two by-product materials: ground granulated blast furnace slag and cement kiln dust were used as replacement materials. Consistency limits, compaction and unconfined compression strength (UCS) tests were conducted. Scanning electron microscopy (SEM) analysis was carried out for the proposed binder to investigate the reaction of products over curing time. Seven curing periods were adopted for all mixtures; 1, 3, 7, 14, 28, 52, and 90 days. The results showed that the strength development over curing periods after cement replacement up to 45–60% was closed to those of the reference specimens. The microphotographs of SEM analysis showed that the formation of Ettringite and Portladite as well as to calcium silicate hydrate gel was obvious at curing periods longer than 7 days reflected that the replacing materials succeed to produce the main products necessary for binder formation.

7

Stabilizacja chemiczna gruntów problematycznych

Szajna Waldemar

Przegląd Budowlany

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2021

|

R. 92, nr 11-12

38--43

PL

W artykule przedstawiono syntetyczne omówienie grupy metod wzmacniania podłoża zwanych stabilizacją chemiczną. Do tej grupy zalicza się między innymi wszelkie odmiany stabilizacji powierzchniowej gruntu spoiwami, wgłębne mieszanie gruntu, a także iniekcje strumieniowe. Cechą wspólną metod stabilizacji chemicznej jest modyfikacja cech fizycznych i mechanicznych podłoża przez wprowadzenie substancji wiążących, wypełniających lub modyfikujących właściwości gruntu rodzimego. Omówiono podstawowe materiały stosowane do stabilizacji oraz zasadnicze reakcje chemiczne, a także procesy zachodzące w podłożu, wspólne dla poszczególnych metod. Przedstawiono także sposoby wprowadzania substancji chemicznych do podłoża, które różnicują tę grupę metod. W celu uporządkowania zagadnień wprowadzono pojęcia gruntów problematycznych oraz gruntów metastabilnych. Omówiono także zakres koniecznych informacji o podłożu, które ma podlegać stabilizacji.

EN

The article presents a synthetic overview of the group of soil improvement methods based on chemical stabilization. This group includes, among others, all types of soil surface stabilization with binders, deep soil mixing, as well as jet grouting. The common feature of chemical stabilization methods is the modification of the subsoil physical and mechanical properties by introducing substances that bind, fill or alter the properties of the native soil. The paper presents basic materials used for stabilization, basic chemical reactions as well as processes occurring in the subsoil, common for individual methods. The methods of applying chemical substances into the subsoil, which differentiate this group of methods, are also presented. In order to organize the issues, the concepts of problematic and metastable soils were introduced. The scope of the necessary information about the subsoil to be stabilized was also discussed.

8

Experimental and finite element analysis of slope stability treated by lime milk (case of El Amir Abdelkader embankment)

Belabbaci Zeyneb, Berrabah Amina, Bouri Djamel Eddine

Mechanics and Mechanical Engineering

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2021

|

Vol. 25, nr 1

77--83

EN

This paper presents an experimental stabilization approach of the landslide that threatens a slope located near the city of El Amir Abdelkader, Ain Temouchent, Algeria. Stabilization is assured by the addition of lime milk, and then a numerical validation of the results with respect to the safety coefficient before and after treatment was performer by “Plaxis” software. Experimental results show that the stabilization by lime milk improves compaction parameters, swelling and shear strength, particularly the cohesion and friction angle, the latter permitting appreciation of the sliding surface on which it is necessary to base the calculation of the safety coefficient before and after treatment. Numerical results indicate that the factor of safety increases with the improvement of the mechanical characteristics c and φ, which are improved by increasing lime milk percentage. The numerical validation using “Plaxis” finite element code gives results that are in perfect agreement with the experimental ones, indicating that this software is a good tool for slope stability study.

9

Biocementacja gruntu przez bakterie ureolityczne - określenie wytrzymałości na ścinanie

Misołek Katarzyna, Popielski Paweł, Affek Katarzyna

Gospodarka Wodna

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2021

|

Nr 6

17--21

PL

Proces mikrobiologicznego uzyskiwania węglanu wapnia (MICP, z ang. Microbially Induced Calcite Precipitation) w celu biocementacji gruntu jest nową, ekologiczną metodą stabilizacji gruntów. Polega ona na wykorzystywaniu aktywności komórek bakterii, które są zdolne do magazynowania produktu metabolicznego CO32-. Jony węglanowe reagują z wolnymi jonami wapnia ze środowiska naturalnego, w skutek czego powstaje struktura minerału. Wykorzystanie bakterii ureolitycznych w celu utworzenia osadu węglanu wapnia okazało się najefektywniejsze. Ta ekologiczna metoda stabilizacji gruntów może znaleźć zastosowanie w zmniejszaniu efektów erozji przy osuwiskach, w budownictwie przy stabilizacji wykopów, a także w naprawie pęknięć w wapieniach. Metoda wzmocnienia gruntu jest obecnie dostosowywana do zastosowania w konstrukcjach hydrotechnicznych. Celem jest zapobieganie mechanicznym uszkodzeniom gruntu z powodu erozji wewnętrznej lub upłynnienia. Artykuł przedstawia badania nad uzyskaniem gruntu ustabilizowanego z wykorzystaniem bakterii ureolitycznych ze środowiska naturalnego. W artykule przedstawiono wyniki badania wytrzymałości gruntu na ścinanie wykonanego z użyciem przyrządu kieszonkowego - ścinarki obrotowej.

EN

Microbially Induced Calcite Precipitation (MICP) used for soil biocementation is a new, ecological method of soil stabilization. This process depends on urease active bacteria which are able to accumulate the metabolic product CO32-. Carbonate ions react with calcium ions from natural environment, eventually forming mineral structure. Using urease active bacteria to form calcium carbonate precipitation turned out to be the most efficient method. This ecological method of soil stabilization can be used to decrease erosion effects in slopes, during construction in excavations and also in crack remediation in limestone. An innovative soil reinforcement method is currently being adapted for hydraulic structures. The objective is to prevent mechanical failure of the soil due to internal erosion or liquefaction. Article presents research in soil stabilization by using urease active bacteria from natural environment.

10

Pressure Settlement Behaviour and Bearing Capacity of Asymmetric Embedded Plus Shaped Footing on Layered Sand

Rawat Priyanka, Dutta Rakesh Kumar

Civil and Environmental Engineering Reports

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2021

|

Vol. 31, no. 3

152--176

EN

The aim of the present numerical study was to analyse the pressure settlement behaviour and bearing capacity of asymmetric plus shaped footing resting on loose sand overlying dense sand at varying embedment depth. The numerical investigation was carried out using ABAQUS software. The effect of depth of embedment, friction angle of upper loose and lower dense sand layer and thickness of upper loose sand on the bearing capacity of the asymmetric plus shaped footing was studied in this investigation. Further, the comparison of the results of the bearing capacity was made between the asymmetric and symmetric plus shaped footing. The results reveal that with increase in depth of embedment, the dimensionless bearing capacity of the footings increased. The highest increase in the dimensionless bearing capacity was observed at embedment ratio of 1.5. The increase in the bearing capacity was 12.62 and 11.40 times with respect to the surface footings F1 and F2 corresponding to a thickness ratio of 1.5. The lowest increase in the dimensionless bearing capacity was observed at embedment ratio of 0.1 and the corresponding increase in the bearing capacity was 1.05 and 1.02 times with respect to the surface footing for footings F1 and F2 at a thickness ratio of 1.5.

11

Sustainable soil stabilization using combination of geotextile, fly-ash and saw dust for pavement subgrade

Sahak A., Singh M., Adhikari A., Hussain S.

Archives of Materials Science and Engineering

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2021

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Vol. 109, nr 1

17--28

EN

Purpose: This paper investigates the combined effect of fly ash, sawdust and geotextile in stabilizing the soil. Design/methodology/approach: A thorough geotechnical testing was carried out in order to study the potent characteristics of soil and soil mixes. The present investigation was set up in two stages. In the first stage, effects of fly ash (5, 10, 15 and 20%), sawdust (2.5, 5 and 7.5%) and layers of geotextile placed at different depths were studied separately to determine their effect on soil stabilization. In the second stage, fly ash, sawdust and geotextile were mixed with soil sample in order to obtain the optimum dosage which can be used for stabilization of soil i.e. their combined effect as stabilizer on soil stabilization. Findings: It was observed that by introducing fly ash, sawdust and geotextile to the soil, the CBR values increase and thickness of pavement layer decreases. It also decreases the amount of stress on subgrade leading to enhancement of pavement stability with cost effectiveness. Research limitations/implications: Economical use of industrial waste has been proposed in the present research which otherwise prove to be a malady to climatic change and human health. From the study, an optimum dosage of fly ash (2.5%) and saw dust (5%) and depth for geotextile (6 cm) has been proposed. Originality/value: The article explores the possibility of a ternary blend, i.e., geotextile, fly-ash and saw dust on effectively stabilizing pavement subgrade. Limited literature was available to address the issue of utilizing the industrial wastes that otherwise pose disposal issues.

12

Improvement of a subgrade soil by using EarthZyme and cement kiln dust waste

Abdulkareem Ahmed Hazim, Eyada Saadoon O., Mahmood Nabeel S.

Archives of Civil Engineering

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2021

|

Vol. 67, nr 2

525--536

EN

Soil stabilization techniques are widely used for road construction to improve the properties of the subgrade materials. Using new additives and stabilizers to improve soil properties can reduce the costs of construction and reduce the possible negative effects of these materials on the environment. The purpose of this study was to evaluate the use of a liquid based nano-material called EarthZyme (EZ) and cement kiln dust (CKD) as admixtures to improve the soil properties. A mixture of two soils was used in this study which were prepared from mixing sand soil and fine-grained soil. Compaction tests were performed on the soil that was stabilized with the CKD to determine the density-water content relationships. Unconfined compression tests were also conducted on specimens without treatment, specimen treated with the CKD only, and specimens treated with the CKD and the EZ after curing period for seven days. The obtained results indicated that adding the CKD to the soil decreased the values of the unconfined compression strength (UCS) from 5 to 15 percent. However, adding the CKD reduced the maximum dry density (MDD) from 10 to 12 %. As discussed herein, soil stabilization with the EZ had insignificant effects on the results obtained from the unconfined compression test.

13

Wzmocnienie podłoża gruntowego pod posadowienie nawierzchni lotniskowej - przykłady praktycznych rozwiązań

Graczyk Mirosław, Kraszewski Cezary, Szymankiewicz Czesław, Łukasiewicz Anna

Builder

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2020

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R.24, nr 7

18--21

PL

Nawierzchnie lotniskowe mają swoją specyfikę, przez co proces ich projektowania i oceny stanu technicznego jest znacznie bardziej skomplikowany w porównaniu z nawierzchniami drogowymi. W przypadku projektowania dróg przeważnie są stosowane typowe rozwiązania katalogowe, podczas gdy nawierzchnie lotniskowe są zawsze projektowane jako rozwiązania indywidualne. Na stan konstrukcji nawierzchni lotniskowej bardzo istotny wpływ ma nośność podłoża gruntowego. Nie zawsze jest ona wystarczająca i wymagane jest wtedy wzmocnienie podłoża. W niniejszym artykule przedstawiono przykłady konstrukcji nawierzchni lotniskowych (płyty postojowe PPS) posadowionych na wzmocnionym podłożu z zastosowaniem różnych technik: stabilizacja gruntów spoiwami hydraulicznymi, konstrukcja podparta betonowymi kolumnami przemieszczeniowymi, konstrukcja na warstwie pianobetonu. W wyniku badań wykonanych konstrukcji i obliczeń uzyskano wartości liczby PCN, które potwierdziły spełnienie wymagań projektowych.

EN

Airport pavements have their own specifics, which makes the process of their design and assessment of the technical condition much more complicated compared to road pavements. In case of road design, typical catalog solutions are used in many situations, while airport pavements are always designed as individual solutions. The condition of the subsoil has a very significant impact on the condition of the airport pavement structure. Bearing capacity of the subsoil is not always sufficient and its improvement is required. This article presents examples of the structure of an airport pavement founded on a reinforced ground using various techniques: soil stabilization with hydraulic binders, pavement supported on concrete displacement columns, geosynthetic geogrid, structure on a foam concrete layer. As a result of tests of the constructions carried out and calculations, the values of the number of PCN were obtained, which confirmed the fulfillment of design requirements.

14

Polepszenie parametrów użytkowych konstrukcji nawierzchni poprzez zastosowanie warstwy stabilizowanej ziarnistym dodatkiem hydrofobowym

Szczepankiewicz Paweł

Magazyn Autostrady

|

2019

|

Nr 5

80--84

PL

W artykule przedstawiono korzyści wynikające ze stosowania stabilizacji gruntu ziarnistym dodatkiem hydrofobowym w kontekście parametrów do indywidualnego projektowania oraz wpływu na trwałość całej konstrukcji nawierzchni. Krótko opisano badanie laboratoryjne modułu sprężystości, będącego jednym z podstawowych parametrów przyjmowanych do projektowania, a także używanym do klasyfikacji stabilizacji wg najnowszej normy na grunty związane hydraulicznie. Pokazano możliwość wykorzystania zaawansowanej metody optycznego pomiaru odkształceń metodą Cyfrowej Korelacji Obrazu dla próbek gruntów stabilizowanych.

EN

The article presents the benefits of stabilizing soil with a powder hydrophobic additive in the context of parameters for individual design and impact on the durability of the entire pavement structure. It also briefly describes the laboratory testing of the modulus of elasticity, which is one of the basic parameters used for pavement design, and also used to classify the stabilization according to the latest European standard for hydraulically bounded soils. Finally the possibility of using the advanced method of optical strain measurement using the Digital Image Correlation method for stabilized soil samples is presented.

15

Metodologia oceny trwałości bezpiecznych i ekologicznych iniekcji gruntowych

Błaszczyński T., Klimaszewski B.

Przegląd Budowlany

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2017

|

R. 88, nr 10

117--120

PL

Technologie iniekcyjne bezpiecznymi żywicami akrylowymi umożliwiają szybkie i bezpieczne rozwiązanie problemów dotyczących uszczelniania lub wzmacniania gruntów przy wykorzystaniu chętnie stosowanych nieskomplikowanych technologii oraz ciężkiego sprzętu. W obliczu braku wiedzy, dotyczącej pełnego spektrum właściwości oraz ograniczeń z tym związanych, autorzy podjęli próbę weryfikacji metodologii badań trwałości iniekcji gruntowych, z wykorzystaniem żywic akrylowych. W artykule zaprezentowane zostały metodologie diagnostyki iniekcji gruntowych według wytycznych krajowych i zagranicznych, umożliwiających łatwiejsze szacowanie jej efektywności oraz trwałości.

16

Stabilizacja skarp i osuwisk

Szruba M., Buca R.

Nowoczesne Budownictwo Inżynieryjne

|

2017

|

Nr 5

42--51

PL

Problematyka ruchów osuwiskowych jest niezwykle złożona, ponieważ dotyka różnych zagadnień z dziedziny nauk przyrodniczych, inżynieryjnych oraz planowania przestrzennego. Osuwiska stanowią przedmiot badań szeregu specjalistów – od zajmujących się nauką o Ziemi przez planistów, projektantów, inżynierów aż po geotechników. Choć ich podejście do problemu bywa odmienne, jednak wszystkim ostatecznie przyświeca jeden cel – dążenie do zminimalizowania ryzyka utraty stateczności stoków i zniszczenia budowli inżynieryjnych.

17

Ekologiczny środek do stabilizacji gruntów spoistych zwiększający ich wytrzymałość i mrozoodporność

Babiak M., Kosno J., Węgliński S.

Materiały Budowlane

|

2017

|

nr 2

24--26

PL

W nawiązaniu do problemu odpowiedniej nośności podłoża pod nawierzchnie drogowe, posadzki, a także fundamenty obiektów budowlanych przedstawiono problematykę stabilizacji słabego gruntu spoistego cementem, z zastosowaniem środka hydrofobizującego. Celem pracy było wykazanie poprawy parametrów gruntów spoistych pod względem wytrzymałości na ściskanie i mrozoodporności.

EN

The article presents the problem of stabilization poor cohesive soil with application of cement and hydrophobizing agent for increase bearing capacity of pavement, construction of floors and the foundations of buildings. The aim of the study was to improve the parameters of cohesive soils in terms of compressive strength and frost resistance.

18

Badanie wytrzymałości na ściskanie gruntowych materiałów kompozytowych torf – popiół lotny – wapno

Brzeziński B.

Materiały Budowlane

|

2017

|

nr 9

140--142

PL

W artykule przedstawiono wyniki badań gruntowych materiałów kompozytowych torf – popiół lotny – wapno hydratyzowane (T-PL-WH) o stałym stosunku PL/T = 0,5 i zmiennym stosunku WH/PL. Wyniki wytrzymałości wykazały istotny wpływ warunków środowiskowych dojrzewania na wytrzymałość na ściskanie. Wraz ze wzrostem stosunku WH/PL zwiększa się wytrzymałość na ściskanie niezależnie od środowiska dojrzewania. Dla stosunku WH/PL = 0,05 wytrzymałość na ściskanie kompozytu wynosi 137,4 kPa i 169,1 kPa w przypadku dojrzewającego w środowisku względnej prężności pary wodnej p/po ≈ 1 i w warunkach powietrzno-suchych. Dla stosunku WH/PL= 0,25 wytrzymałość na ściskanie wynosi odpowiednio 167,4 kPa i 260,8 kPa.

EN

The article presents tests results of ground composite materials: peat – volatile ash – hydrated lime (T-PL-WH) with a stable ratio PL/T = 0,5 and a variable ratio WH/PL. The durability results have shown a considerable influence of environmental conditions of curing on compressive durability. The rise in the ratio WH/PL is paralleled by the rise in the compressive durability regardless of a curing environment. For the ratio WH/PL = 0,05 the compressive durability of the composite is 137,4 kPa. In case of composites curing in an environment of relative vapor pressure p/po ≈ 1 and dry air conditions the compressive durability is 169,1 kPa. For the ratio WH/PL = 0,25 the compressive durability is 167,4 kPa i 260,8 kPa respectively.

19

Badania wytrzymałości stabilizowanych gruntów organicznych w warunkach laboratoryjnych

Topoliński S., Gorączko A.

Magazyn Autostrady

|

2017

|

Nr 11-12

52--55

PL

W artykule przedstawiono przegląd wybranych metod laboratoryjnych badań wytrzymałości na jednoosiowe ściskanie stabilizowanych gruntów organicznych stosowanych w stabilizacji gruntów metodą mieszania gruntu in situ. Przeanalizowano wpływ doboru spoiwa i sposobu projektowania mieszanki, formowania i warunków dojrzewania próbek w zależności od rodzaju stabilizacji. Przedstawiono także sposób określenia wytrzymałości badanych próbek oraz interpretacji wyników.

EN

The paper reviews selected standard requirements for uniaxial compression strength testing of stabilized organic soils used in in situ soil mixing. The binder selection and design of mixture, molding and maturation conditions according to the type of stabilization have been analyzed. The article also discusses the determination of the strength of test samples and the interpretation of results.

20

FEM based analysis of wing wall to culvert connection

Voitenko P., Anderson J. B.

Builder

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2017

|

R.21, nr 11

78--81

EN

As part of transportation systems, culverts are subjected to complex load conditions such as earth pressure and traffic live load. In addition, culverts may experience differential settlement of underlying soils, hydrostatic load, and aggradation/degradation scour. Combinations of these effects may cause crack formation or even structural failure. The objective of this paper is to study factors that lead to crack formation in the culvert-wing wall connection immediately after construction. Finite element models (FE) with Plaxis 3D software were used to analyze the stress distribution along the wing wall connection under different load scenarios and geometries. Mohr-Coulomb (MC) and Hardening soil (HS) non-linear material models were utilized. Tension stresses were occurred at the top of the wing wall as well as out of plane rotation away from the culvert, contributing to cracks as observed in the field.