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This paper describes the effect of factors on the strength characteristics of cement treated clay from laboratory tests performed on cement mixed clay specimens. It is considered that several factors such as soil type, sample preparing method, quantity of binder, curing time, etc. can have an effect on strength characteristics of cement stabilized clay. A series of unconfined compression tests have been performed on samples prepared with different conditions. The results indicated that soil type, mixing method, curing time, dry weight ratio of cement to clay (Aw), and water‐clay to cement (wc/c) ratio were main factors which can have an influence on unconfined compressive strength, modulus of elasticity, and failure strain of cement stabilized clay. Unconfined compressive strength of soil‐cement samples prepared from dry mixing method was higher than those prepared from wet mixing method.

This paper aims to investigate the behaviour of geosynthetic reinforced deep cement mixed (DCM) column-supported embankments constructed over soft soils.

Coupled consolidation analyses based on the finite element method are carried out assuming that the soil and DCM columns are fully saturated porous mediums. In the first part of the paper, a case study of an embankment constructed over a very soft soil deposit in Finland is presented. Two- and three-dimensional finite element models for the case study are developed including isolated and attached DCM columns beneath the embankment to capture the arching mechanism between DCM columns. The model simulations were carried out considering the actual staged construction procedure adopted in the field. Finite element predictions show good agreement with field data and confirm that the load transfer is mainly between attached columns beneath the embankment. Next, the significance of geosynthetic reinforcement on the load transfer mechanism is investigated. Finally, the influence of permeability of columns and soft soil on the performance of geosynthetic reinforcement column-supported embankments is studied.

Results demonstrate that the excess pore pressure dissipation rate is fast in DCM column-improved ground compared to the same case without any columns, although the same permeability is assigned to both DCM columns and surrounding soft soil. When DCM column permeability exceeds soil permeability, excess pore pressure dissipation rate shows a remarkable increase compared to that observed when the DCM column permeability is less than or equal to the permeability of surrounding soft soil. [ ]

This paper investigates the contribution of permeability and geosynthetic layer on the vertical load transfer mechanism of the embankment and modelling issues related to application of the embankment load and the properties of the cement-improved columns.

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.

Whereas the Minister of Labour (hereafter in this Order referred to as the “Minister”) has received from the Brush and Broom Wages Council (Great Britain) the wages regulation proposals set out in Schedules 1 and 2 hereof;

There is an increase in greenhouse gasses and global climate change is frequently reported on. What can be done? Certainly to try and reduce the carbon footprint, which is not a new topic, by encouraging applications and activities for concrete during its lifetime (Portland Cement Association, 2019). This study aims to focus on introducing CO₂ to normal and fly ash concrete and thus investigating the effect on the carbon footprint of the samples and the effectiveness of the CO₂ introduction methods, namely, carbonated water addition during the mixing process and by means of an infusion pipe directly into the concrete when the samples are casted and have been casted.

The feasibility of carbon dioxide storage within concrete is determined by investigating the effects of introduced carbon dioxide into concrete samples and the effectiveness of the concrete at storing carbon dioxide. The concrete was mixed in a 1:3:3 ratio for the OPC or blended 52.5 R cement:sand:stone (22 mm) with a 28 day strength of 50 MPa. Samples were also prepared containing low-grade fly ash cement contents ranging from 15% to 60%. CO₂ was introduced to the concrete via carbonated mixing water and an infusion pipe system directly to the hardening concrete cubes. In total, 16 g CO₂ bicycle carbon dioxide inflators and valve system were used to infuse the concrete over a period of a week until the canister was emptied with valve release on the lowest setting. A compression test was carried out to determine the strength of the concrete cubes with, and without, the introduction of carbon dioxide. Results were also obtained using a scanning electron microscope (SEM) and energy dispersive x-ray spectrometer (EDS) to determine how the carbon dioxide changed the microscopic composition and chemical composition of the concrete. A microcontroller with carbon dioxide sensors was used to gather carbon dioxide emission data for a period of three months.

The compressive strength tests show by introducing carbon dioxide to the concrete, the compressive strength has increased by as much as 13.86% as expected from the literature. Furthermore, by infusing carbon dioxide with the fly ash blended cement, will give a higher strength compared to the control with ordinary portland cement. This correlates to an overall reduction in cost for the structure. The optimal fly ash content for the control with minimal strength degradation is 30%. Where the optimal fly ash content for the concrete with carbon dioxide stored within, is 45%. The SEM analysis showed the concrete with sequestered carbon dioxide has significantly more calcium silicate hydrate (C-S-H) gel formation, thus the strength increase. Furthermore, the carbon dioxide emission test showed the concrete with infused carbon dioxide stores carbon dioxide more efficiently compared to the control sample. With the data showing the infused sample releases 11.19% less carbon dioxide compared to the control sample. However, the carbonated water sample releases 20.9% more carbon dioxide when compared to the control sample. Thus the introduction of carbon dioxide by means of infusion is more effective.

This is a practical pilot investigation of carbon dioxide introduction via two methods, one being infusion of CO₂ into normal concrete and fly ash concrete and two, mixing normal and fly ash concrete with carbonated water. These results show, cheaper cement can be used to achieve equivalent or better strength. This can help in the reduction of the construction industry’s carbon footprint.

By reducing the construction industry’s carbon footprint with this research results, a saving can not only be made financially in the construction industry, but this will help to preserve our environment for future generations.

The study aims to analyse the stability of embankments over the improved ground with stone column (SC) and pervious concrete column (PCC) inclusions using limit equilibrium method. The short-term stability of PCC-supported embankment system is rarely addressed. Therefore, the factor of safety (FOS) of column-supported embankment system is calculated using individual column and equivalent area models.

The stability analysis of column-supported embankment system is conducted using PLAXIS LE 2D. The various geometrical and shear strength parameters influencing the FOS of these embankment systems such as diameter of columns, spacing between columns, embankment height, friction angle of column material, undrained cohesion of weak ground and cohesion of PCC are considered.

The critical failure envelope of PCC-supported embankment system is observed to be of toe failure, whereas the failure envelope of stone column-supported embankment system is generally of deep-seated nature.

It is found that for PCC embankment system, FOS and failure envelope are not influenced by the geometrical/shear strength parameters other than height of embankment. However, for stone column-supported embankment system, FOS and failure envelope are dependent on all the shear strength and geometrical parameters considered in this study.

Several constitutive models are available in the literature to describe the mechanical behaviour of cement stabilized soils. However, difficulties in implementing such models within commercial finite element programs have hindered their application to solve related boundary value problems. Therefore, the aim of this study is to implement a constitutive model, which has the capability to simulate cement stabilized soil behaviour, into the finite element program ABAQUS through the user material subroutine UMAT.

After a detailed review of existing constitutive models for cement stabilized soils, a model based on the elasto‐plastic theory and the extended critical state concept with an associated flow rule is selected for the finite element implementation. A semi‐implicit integration method (cutting plane algorithm) with a continuum elasto‐plastic modulus and path dependent stress prediction strategy has been used in the implementation. The performance of the new finite element formulation of the constitutive model is verified by simulating triaxial test data using the finite element program with the new implementation and predictions from constitutive equations as well as experimental data.

The paper provides the implementation procedure of the constitutive model into ABAQUS but this method is useful for the implementation of any other constitutive model into ABAQUS or any other finite element program. Simulated results for the volumetric deformation of cement stabilized soils show that the cement stabilized soils do not obey the associated flow rule at high confining pressures. The parametric study shows that the influence of cementation increases the brittle nature and the bearing capacity of treated clay. In addition the results show that proposed finite element implementation has the ability to illustrate key features of the cement stabilized clay.

This paper presents an implementation of an elasto‐plastic constitutive model, based on the extended critical state concept, for cement stabilized soils into a finite element programme, which has been identified as an important and challenging topic in computational geomechanics. This implementation is useful in solving boundary value problems in geomechanics involving cement stabilized soils, incorporating key characteristics of these soils.

The purpose of this paper is to investigate the empirical association between the tone of earnings announcements and a company’s membership in a sin industry.

This study constructs a model of the determinants of earnings announcement tone to examine the impact of sin industry membership on earnings announcement tone. An interaction term between CEO power (CEO–chairman duality) and sin industry membership is used to test whether CEO power moderates the strength of the association. The earnings announcements tone is measured using the spread in the proportion of positive and negative words. The category of sin industry includes not only industries such as tobacco, gambling and alcohol, but also industries associated with emerging environmental, social, and ethical issues (i.e. firearms, oil and cement).

The analysis of a sample of US firms from the 1994 to 2013 period shows that the tone of earnings announcement is less optimistic for companies in sin industries, but this association is weaker for companies that are led by powerful CEOs. The results remain robust to alternative definitions of sin industry membership and CEO power (CEO tenure) and to alternative model specifications.

The findings suggest that although sin companies cannot change the nature of their business, the management of such companies, in general, uses a less aggressive tone in their earnings announcements. These results further investors’ understanding of sin companies’ reporting behavior.

The purpose of this article is to analyze the state-of-the art in a systematic way, identifying the main research groups and their related topics. The types of studies found are fundamental for understanding the application of artificial neural networks (ANNs) in cemented soils and the potential for using the technique, as well as the feasibility of extrapolation to new geotechnical or civil and environmental engineering segments.

This work is characterized as being bibliometric and systematic research of an exploratory perspective of state-of-the-art. It also persuades the qualitative and quantitative data analysis of cemented soil improvement, biocemented or microbially induced calcite precipitation (MICP) soil improvement by prediction/modeling by ANN. This study sought to compile and study the state of the art of the topic which possibilities to have a critical view about the theme. To do so, two main databases were analyzed: Scopus and Web of Science. Systematic review techniques, as well as bibliometric indicators, were implemented.

This paper connected the network between the achievements of the researches and illustrated the main application of ANNs in soil improvement prediction, specifically on cemented-based soils and biocemented soils (e.g. MICP technique). Also, as a bibliometric and systematic review, this work could achieve the key points in the absence of researches involving soil-ANN, and it provided the understanding of the lack of exploratory studies to be approached in the near future.

Because of the research topic the article suggested other applications of ANNs in geotechnical engineering, such as other tests not related to geomechanical resistance such as unconfined compression test test and triaxial test.

This article systematically and critically presents some interesting points in the direction of future research, such as the non-approach to the use of ANNs in biocementation processes, such as MICP.

Regarding the social environment, the paper brings approaches on methods that somehow mitigate the computational use, or elements necessary for geotechnical improvement of the soil, thereby optimizing the same consequently.

Neural networks have been studied for a long time in engineering, but the current computational power has increased the implementation for several engineering applications. Besides that, soil cementation is a widespread technique and its prediction modes often require high computational strength, such parameters can be mitigated with the use of ANNs, because artificial intelligence seeks learning from the implementation of the data set, reducing computational cost and increasing accuracy.

This paper presents the physical, mathematical and numerical models forming the main structure of the numerical analysis of the thermal, hydral and mechanical behaviour of normal, high‐performance concrete (HPC) and ultra‐high performance concrete (UHPC) structures subjected to heating. A fully coupled non‐linear formulation is designed to predict the behaviour, and potential for spalling, of heated concrete structures for fire and nuclear reactor applications. The physical model is described in more detail, with emphasis being placed upon the real processes occurring in concrete during heating based on tests carried out in several major laboratories around Europe as part of the wider high temperature concrete (HITECO) research programme. A number of experimental and modelling advances are presented in this paper. The stress‐strain behaviour of concrete in direct tension, determined experimentally, is input into the model. The hitherto unknown micro‐structural, hydral and mechanical behaviour of HPC/UHPC were determined experimentally and the information is also built into the model. Two examples of computer simulations concerning experimental validation of the model, i.e. temperature and gas pressure development in a radiatively heated HPC wall and hydro‐thermal and mechanical (damage) performance of a square HPC column during fire, are presented and discussed in the context of full scale fire tests done within the HITECO research programme.