Compaction Conditions Research Articles

Control Parameters for the Long-Term Tensile and Compressive Strength of Stabilized Sedimentary Silt

The yellow-layer soils of the Guabirotuba formation in Brazil are problematic due to their expansive nature and low-bearing capacity. There has been little exploration into stabilizing these soils using a calcium-based binder. In addition, existing methods for dosing lime to fine and coarse-grained soils using the porosity-to-lime index (η/Liv) have primarily focused on non-optimal compaction conditions to determine the split tensile and compressive strengths and empirical relationships between both tests while ignoring the study of optimal lime-soil mixes compaction conditions. Therefore, the objective of this research is to examine the unconfined compressive (qu) and split tensile (qt) behavior of a traditional Guabirotuba yellow silt stabilized with dolomitic hydrated lime (L) under standard, intermediate, and modified effort conditions and the correlation between qu and qt. The lime-soil blends were cured for up to 180 days, and 3-9% lime percentages were used under optimum compaction conditions (maximum dry density and optimum water content). The porosity/lime index (η/Liv), a semi-empirical index, was utilized to investigate the evolution of qu and qt over the short and long term. η/Livvaried between 6-25% by volume. Furthermore, the qt/qu index was calculated to be between 0.12-0.20, depending on the curing time, independent of lime addition and compaction effort used. Equations well-suited to a power function dosing qt and qu based on curing time and η/Livindex was proposed. Finally, some dosages of soil-lime mixtures were proposed for possible applications in geotechnical engineering, applying the porosity and volumetric binder index in optimal compaction conditions, which had not been applied before for lime-improved soils. Doi: 10.28991/CEJ-2023-09-04-03 Full Text: PDF

Effects of compaction conditions and external stress on the one-dimensional swelling behaviors of expansive clay

Effects of compaction conditions and external stress on the one-dimensional swelling behaviors of expansive clay

Remarks on compactness conditions and their application

We review typical compactness conditions used in variational techniques and some of their properties, and the relationships between them. In particular, we provide some new insights into results related to the Palais-Smale and Cerami conditions, and their comparison. See also https://ejde.math.txstate.edu/special/02/c3/abstr.html

On the role of compaction in disputes over the quality of the supplied concrete

This paper evaluates the effect of poor compaction on the compressive strength, sorptivity, gas permeability and accelerated carbonation resistance of bulk concrete in structures, framed in the scenario of disputes over the quality of the supplied concrete. For that purpose, several real-scale elements (beams, columns and slabs) were cast with concrete incorporating Portland-limestone cement and fly ash addition, covering a wide range of slumps (35–123 mm) and compressive strengths (25–65 MPa). The elements were then subjected to different compaction conditions (standard vibration and no vibration), and later cored for concrete testing. A new compaction indicator that overcomes the main practical limitations associated with the determination of the excess voidage of concrete is proposed, as well as new factors for correcting the effects of on-site compaction in the estimation of the potential carbonation resistance and the compressive strength of concrete. It is also shown that vibration no longer improves the quality of bulk concrete in structures for slumps above ~ 140 mm, which suggests that, in cases of dispute where greater slumps are specified, no correction for compaction should be needed in the estimation of the potential properties of concrete.

Mechanical and biotic reclamation strategies for a post‐mine temperate grassland

AbstractGlobal energy production is in high demand and is expanding its development into new landscapes, including grasslands. This expansion has intensive impacts on aboveground and belowground components of grasslands which need to be addressed during reclamation to promote long‐term ecological integrity. This study was conducted to ascertain how alternative reclamation practices may improve soil structure (i.e., compaction) while aiding in the creation of conditions that are conducive to both the establishment and continued growth of native grassland plant species. The grassland was reclaimed with different combinations of seeding mixtures (grass or grass and forb), ripping techniques (subsoil ripping or topsoil ripping), and the integration of mulch into the soil profile. Year, seed mixtures, and ripping techniques and their interactions significantly affected community composition and species diversity. Topsoil‐ripping and grass‐forb treatment had a higher association with native, perennial grasses while subsoil‐ripping and grass treatment favor more short‐lived species. Similar trends persisted across penetration resistance and soil moisture readings where topsoil‐ripping and grass‐forb treatment were different from subsoil‐ripping and grass treatments (p ≤ 0.10). Additionally, Kentucky bluegrass, an invasive grass species, increased by 76% over 1 year and was more common in the topsoil‐ripping and grass‐forb treatments. While early in the reclamation process, results suggest topsoil‐ripping and grass‐forb treatment are promising combination reclamation practices that can establish a native grassland community and initiate the improvement of compacted soil conditions.

Mappings Ideal of Type the Domain of Generalized p , q -Euler Matrix in c 0 and c

We develop new Banach sequence spaces e 0 a , b p , q and e c a , b p , q derived by the domain of generalized p , q -Euler matrix E a , b p , q in the spaces of null and convergent sequences, respectively. We investigate some topological properties and inclusion natures related to these spaces. We construct bases and obtain α , β , and γ -duals of the spaces e 0 a , b p , q and e c a , b p , q . Certain classes of matrix transformations are characterized from e 0 a , b p , q and e c a , b p , q to Z ∈ ℓ ∞ , c , c 0 , ℓ 1 , ℓ k . We obtain essential conditions of compactness of operators from e 0 a , b p , q and e c a , b p , q to Z ∈ ℓ ∞ , c , c 0 , ℓ 1 , b s , c s , c s 0 . Finally, under a definite functional ϱ and a weighted sequence of positive reals δ , we define a new sequence space e 0 a , b p , q , δ ϱ . Certain geometric and topological properties of this space along with the eigenvalue distribution of mapping ideals due to this space and s -numbers are investigated.

The third solution for a Kirchhoff-type problem with a critical exponent

The aim of this paper is to analyze the multiplicity of solutions for a nonhomogeneous Kirchhoff-type problem on R4 with a critical exponent. The first two positive solutions are deduced by using the variational method, and the third solution is found with the help of Brezis-Lieb's lemma and Mazur's lemma. Moreover, we obtain a new compactness condition and improve on the existing results in the literature.

Subordination principle and approximation of fractional resolvents and applications to fractional evolution equations

This paper first analyzes and treats the subordination principle and the approximation of fractional resolvents, extending and perfecting the theory of resolvent. Then, the approximation solvability method and the resolvent technique are developed to investigate the existence of mild solutions to a Riemann-Liouville type fractional nonlocal evolution system without the compactness condition. Moreover, effectiveness of our mentioned findings is supported by an example about a fractional diffusion system.

Comparison of Some Physical Properties of Soil and River Sediment

In this research, a comparison of some physical properties of two natural media was made, namely, a selected soil sample from the northwestern segment of the Skopje valley and a sample of river sediment from the river Vardar. The primary parameters of the samples are determined, such as: granulometric composition, specific mass and volume mass in different compacted condition. The secondary physical characteristics are followed, which are a consequence of the previously listed, which are the porosity of the samples and the capillary characteristics. These, further define the following characteristics of the media: maximum water permeability, characteristics of the water transport process and heat transfer through the examined sample layer. Simultaneously, the changes of temperature and moisture at a defined point of the experimental layers are monitored (under appropriate experimental conditions, namely, an emphasized / amplified ΔT is set) and the phenomena are explained.

Zero-sum games involving teams against teams: Existence of equilibria, and comparison and regularity in information

Many emerging problems involve teams of agents taking part in a game. Such problems require a stochastic analysis with regard to the correlation structures among the agents belonging to a given team. In the context of standard Borel state, measurement and action spaces (thus, including real vector spaces and finite spaces), this paper makes the following contributions for two teams of finitely many agents taking part in a zero-sum game: (i) An existence result will be presented for saddle-point equilibria in zero-sum games involving teams against teams when common randomness is assumed to be available in each team with an analysis on conditions for compactness of strategic team measures to be presented. (ii) Blackwell’s ordering of information structures is generalized to n-player teams with standard Borel spaces, where correlated garbling of information structures is introduced as a key attribute; (iii) building on this result Blackwell’s ordering of information structures is established for team-against-team zero-sum game problems. (iv) Finally, continuity of the equilibrium value of team-against-team zero-sum game problems in the space of information structures under total variation is established.

Realizing Holistic Charging–Discharging for Dendrite-Free Lithium Metal Anodes via Constructing Three-Dimensional Li+ Conductive Networks

Lithium (Li) metal is a promising candidate for next-generation anode materials with high energy densities. However, Li dissolution/deposition processes are limited at the upper surface in contact with the electrolyte, which brings a locally high current density and then results in dendritic Li growth. This restraint of the local surface reaction during cycling has not been solved by commonly used modification strategies. In this study, a three-dimensional (3D) Li+ conductive skeleton is activated from atomic layer deposition (ALD) coating Li3PO4 (LPO) on the surface of the Ni foam (LPNF). Then, the skeleton is efficiently constructed in the Li metal anode by the lower-temperature Li infusion. Ionic conductor LPO layers and electronic conductor Ni fibers supply charge transport channels between the electrolyte and the internal Li. The mixed conductive network realizes holistic charge transfer, which is proved by in situ scanning electron microscopy experiments. In virtue of dispersive dissolution/deposition and optimized electrochemical kinetics brought by a Li+ conductive network, the composited Li electrode presents an excellent symmetric battery cycling stability (over 1200 h) and enhanced rate performances (stable cycling even at 10.0 mA cm-2). When matching with a LiCoO2 (LCO) cathode, LCO||Li@LPNF full batteries exhibit a capacity retention of 80.8% over 250 cycles. During cycling, there was no evidence of dendrite growth and the remaining Li in the composited anode showed a smooth, compact, and well-combined condition with LPNF. Through constructing a 3D Li+ conductive network, the composited Li metal anode breaks through the limit of the local surface reaction; this work proposes a novel insight of realizing holistic charging/discharging for the dendrite-free Li metal anode.

Lightweight Expanded Clay Aggregate (LECA) as replacement materials for geotechnical application

Settlement is a common geotechnical problem occurs in soft soils. The replacement method is the easiest way to improve this problematic soil. This technique is carried out by removing the unwanted part of the soil and replacing it with a more suitable material or soil. This study focuses on using Lightweight Expanded Clay Aggregate (LECA) as a construction material to replace normal sand and aggregate in filling work. LECA is one of the best alternatives that can be used to improve soil properties because it is lightweight, strong and environmentally friendly. However, there are no specific guidelines for the LECA replacement in filling work. Therefore, this study was conducted to develop the construction procedures and LECA replacement requirements for geotechnical application in Malaysia. LECA aggregates have been used as a filling material to solve the settlement problem at Masjid At-Taqwa, Teluk Intan, Perak, Malaysia. LECA samples were collected from different location at different compaction levels for inspection of physical properties and quality of compaction examination. The level of compaction effort performed on LECA replacement represents by the number of passes. The relationship in compaction conditions related to LECA replacement is determined by two graphs namely LECA Compaction Effort and Targeted Compaction Level. The compaction quality of LECA aggregate filling work can be checked using Lightweight Deflectometer (LWD). The maximum desired density can be determined in advance. With reference to the LECA Compaction Effort plot established in this study, the number of passes that need to be performed during the placement work can be planned according to the desired compact density. Whereas, the compaction level, R% can be predicted based on the Target Compaction Level plot. An LWD test should then be carried out to ensure that the compacted density reaches the required level.

The Well-posedness and the Regularity of Global Attractor for a Couple Stress Fluid Through Porous Layer with the Local Thermal Non-equilibrium Effect

In the article, we aim to investigate the well-posedness of solution and the regularity of the global attractor for the couple stress fluid in saturated porous media with the local thermal non-equilibrium effect. To be more specific, we firstly show the existence and uniqueness of global weak solution to the model by making use of the standard Galerkin method. Second, relying on verifying the uniformly compact condition required, we prove the existence of the global attractor of the model in the space where the weak solution resides. Finally, we improve the regularity of global attractor by uniformly compact condition and obtain the \(C^{\infty}\) attractor for the model.

Analysis of fractional stochastic evolution equations by using Hilfer derivative of finite approximate controllability

<abstract><p>The approximate controllability of a class of fractional stochastic evolution equations (FSEEs) are discussed in this study utilizes the Hilbert space by using Hilfer derivative. For different approaches, we remove the Lipschitz or compactness conditions and merely have to assume a weak growth requirement. The fixed point theorem, the diagonal argument, and approximation methods serve as the foundation for the study. The abstract theory is demonstrated using an example. A conclusion is given at the end.</p></abstract>

EFFECT OF SEDIMENT SIZE ON SANDBAR MORPHOLOGY IN DIFFERENT COMPACTION CONDITIONS

EFFECT OF SEDIMENT SIZE ON SANDBAR MORPHOLOGY IN DIFFERENT COMPACTION CONDITIONS

Weighted Schrödinger-Kirchhoff type problem in dimension 2 with non-linear double exponential growth

In this work, we study the weighted Kirchhoff problem {g(?B(?(x)|?u|2 + V(x)u2)dx) [?div(?(x)?u) + V(x)u] = f (x, u) in B u > 0 in B u = 0 on ?B, where B is the unit ball in R2, ?(x) = log e |x| , the singular logarithm weight in the Trudinger-Moser embedding, g is a continuous positive function on R+ and the potential V is a continuous positve function. The nonlinearities are critical or subcritical growth in view of Trudinger-Moser inequalities. We prove the existence of non-trivial solutions via the critical point theory. In the critical case, the associated energy function does not satisfy the condition of compactness. We provide a new condition for growth and we stress its importance to check the min-max compactness level.

Компактность в пространстве квази абсолютно непрерывных функций

In this paper we introduce the notion of a quasi-continuous function on a closed segment and obtain the set compactness condition in the functions quasi-absolutely continuous space on a closed segment. The class completeness allows us to replace a continuous function by a approxima-tions sequence, each of which is "simpler" than the original one. The differential equations investi-gating solutions simplifying process problem is solved, for which a constructing an absolutely con-tinuous function method is proposed.

ON STRONGLY INDEFINITE SCHRÖDINGER EQUATIONS WITH NON-PERIODIC POTENTIAL

This paper is concerned with the non-periodic superlinear Schrödinger equation $ -\Delta u+V(x)u=f(x, u) $, $ u\in H^{1}(\mathbb{R}^{N}) $. Here, the Shrödinger operator $ -\Delta + V $ is strongly indefinite, that is, possesses a infinite dimensional negative space, which leads to more difficulty in verifying the compactness conditions. We prove the existence, as well as multiplicity provided $ f(x, t) $ is odd in $ t $, of solutions via variational methods.

On a general class of $ n $th order sequential hybrid fractional differential equations with boundary conditions

<abstract><p>This manuscript is related to consider a general class of $ n $th order sequential hybrid fractional differential equations (S-HFDEs) with boundary conditions. With the help of the coincidence degree theory of topology, some appropriate results for the existence theory of the aforementioned class are developed. The mentioned degree theory is a powerful tool to investigate nonlinear problems for qualitative theory. A result related to Ulam-Hyers (U-H) stability is also developed for the considered problem. It should be kept in mind that the considered degree theory relaxes the strong compact condition by some weaker one. Hence, it is used as a sophisticated tool in the investigation of the existence theory of solutions to nonlinear problems. Also, an example is given.</p></abstract>

Compaction Prediction for Asphalt Mixtures Using Wireless Sensor and Machine Learning Algorithms

Compaction is a critical step in asphalt roadway construction to determine the pavement’s quality and service life. Current field compactions are mainly based on test strips and engineers’ experiences. Such empirical-based approaches sometimes cause compaction problems especially when new materials are implemented. Intelligent compaction (IC) technology was invented to improve compaction quality. The real-time collection and visualization of the pavement responses and temperature can greatly improve compaction uniformity. However, the material viscoelastic property and the complex pavement structure still hinder the establishment of the correlation between the Intelligent Compaction Measurement Value (ICMV) and the compactability of asphalt pavement. This paper aims to establish compaction prediction models based on machine learning (ML) algorithms and sensing technology. Given the strong correlation between the mixture’s compactability and the particle compaction characteristics, a particle-size wireless sensor, SmartRock, was used to collect the particle kinematic behaviors during compaction. 11 asphalt mixtures were compacted with an embedded SmartRock sensor. Three ML models and three dataset scenarios were applied to predict the compaction condition, and a higher than 98% prediction accuracy was achieved. The results revealed that combining the ML approach and sensing data is appropriate and practical for predicting the compaction condition of the asphalt mixture. Future studies shall further evaluate the algorithm based on field compaction data so that intelligent sensing technology can be implemented to improve compaction quality.