Construction Engineering and Management Commons^™

Study On Alkali Excitation Mechanism Of Large Dosage Slag Fine Powder, Mei Yang

Journal of China & Foreign Highway

To reveal the alkali excitation mechanism of high-dosage slag, this paper combines a three-factor, three-level orthogonal design with macro- and micro-performance tests and microstructure analysis. The effects of different activators, including Ca(OH)2, Na2SiO3, Na2SO4, and CaSO4, in single and dual combinations on the initial and final setting times, pore solution pH, and strength of concrete were explored. The results show that the impact on the strength of hardened paste of composite cementitious materials is ranked as: activator type > dosage > dual-mix ratio. The optimal dual-mix dosage is 4%, with the best combination being Ca(OH)2 and Na2SiO3 at a ratio of 5:1. …

Dynamic Load Response Analysis Of Rubber Powder Modified Asphalt Mixture, Yang Sanqiang, Sun Shuang, Li Qian, Liu Xinlei, Qin Lusheng

Journal of China & Foreign Highway

To investigate the mechanical response of rubber powder modified asphalt pavement under dynamic loads, this paper, based on the “Full-Scale Accelerated Pavement Loading Testing” project, designed experimental schemes for asphalt mixtures with varying rubber powder contents. The paper employed accelerated loading test equipment to evaluate the stress and deformation of pavement structures, obtaining dynamic strain response data to analyze the strain response patterns of various structural layers. Combining finite element numerical simulations and a custom loading program, the paper examined the dynamic responses of rubber powder modified asphalt pavements under variable temperature conditions. The results show that through microscopic testing, …

Aging Asphalt Concrete Cracking Performance Under Different Cyclic Loading Frequencies, Yan Jingchen, Ma Yanpei, Yan Junjie

Journal of China & Foreign Highway

Using digital speckle technology, this paper examines the crack propagation behavior of asphalt concrete under repeated loading, analyzing the crack propagation mechanism from macro- and micro-perspectives under different aging conditions and loading frequencies for four types of asphalt concrete. The results show that the basalt fiber-reinforced asphalt concrete beam specimens delay the onset of the unstable crack propagation phase, thus extending the service life of the asphalt concrete. Aging accelerates the progression of asphalt concrete to the unstable crack propagation point, advancing this stage by 4%-5%. Under repeated loading frequencies of 5 Hz, 10 Hz, and 15 Hz, the damage …

Study On Microstructure Of Asphalt Modified By Oil‐Coal Blend, Guo Pengfei, Zhou Xinfeng

Journal of China & Foreign Highway

To investigate the microstructure and modification mechanism of asphalt modified with oil-coal blend, SK-90# asphalt was mixed with 5%, 10%, 15%, 20%, and 25% (external blending method) oil-coal blend to produce modified asphalt. The performance and microstructural changes of the modified asphalt were analyzed using contact angle testing, infrared spectroscopy, cross-sectional SEM, and X-ray photoelectron spectroscopy. The results show that the oil-coal blend exhibits good compatibility with asphalt. During the modification process, esterification reactions occurred, resulting in a decrease in hydroxyl-containing aromatic compounds and an increase in carbonyl-containing aromatic compounds. Macroscopically, the oil-coal blend-modified asphalt demonstrated excellent high-temperature performance.

Design And Development Of Two And Three Dimensional Integration System For Highway Based On Webgis, Che Defu, Zhou Huajun

Journal of China & Foreign Highway

To address the inefficiencies, lengthy cycles, and high resource demands in the process of determining the annual project database for highway maintenance quotas in Liaoning Province, a 2D and 3D integration system for highways based on WebGIS was designed and developed. This system not only provides a macroscopic view of the geographic distribution and overall characteristics of highways but also offers a detailed and intuitive representation of the spatial relationships and conditions of roadbeds and pavement damage. The system meets the needs of modern highway management and can serve as a reference for other highway maintenance quota tasks.

Research On Influence Factors And Efficiency Analysis Of Expressway Maintenance Marketization, Zhong Wen, He Shoukui, Wang Xiaodong

Journal of China & Foreign Highway

To promote market-oriented reform of highway maintenance, this paper investigates its influencing factors and outcomes and proposes an evaluation model for assessing its effects. A panoramic analysis method within a three-dimensional framework was employed to determine the evaluation content. Drawing on the balanced scorecard concept, the analysis incorporates four dimensions: business, user, internal management, and learning and growth, with the innovative addition of a social responsibility dimension to construct an evaluation indicator system. Subsequently, a cloud-based extension model was developed to evaluate the effectiveness of expressway maintenance marketization and calculate the evaluation grade. Empirical analysis was conducted using data from …

Analysis Of Expressway Routine Maintenance Performance Management Based On Dea, Li Yuhuan, Shi Xiaoli, Gao Nan

Journal of China & Foreign Highway

To allocate maintenance resources efficiently and improve management levels, this paper examines the maintenance performance and improvement strategies of routine maintenance projects for 23 expressways in Shaanxi Province using 2018 operational maintenance data and data envelopment analysis. The results show that for some inefficient subsidiaries, traditional radial- and slack-based performance improvement methods are challenging and impractical in the short term. Therefore, a scenario-dependent model-based long-term incremental improvement strategy is proposed. By leveraging relative improvement values, this strategy enables phased improvements for inefficient subsidiaries. It provides a feasible approach for subsidiaries to set lower short-term performance improvement targets while achieving gradual …

Study On The Minimum Radius Of Vertical Curve Of Highway Main Line Entrance Section Based On Merging Sight Distance, Li Yang, Zhao Yemei, Chen Tianxing

Journal of China & Foreign Highway

Given the limited research on the vertical curve radius of highway mainline entrance sections and the lack of differentiation between entrance and exit sections in existing studies, this paper identifies merging sight distance as the primary influencing factor for the vertical curve radius of entrance sections. Using merging sight distance as the control condition, the vertical curve radius of entrance sections was studied. A safety merging sight distance calculation model for highway mainline entrance sections was established by analyzing the traffic behavior characteristics of vehicles on the entrance mainline and considering drivers’ psychological and physiological characteristics. The sight distance model …

Framework For Applicability Of Fidic Red Book (1999) For Contracts Governed By Law No. 182 Of The Year 2018 For Regulating Contracts Concluded By Public Entities, Fredy Ayad

Theses and Dissertations

An administrative contract is a type of contract that the administrative body enters in order to achieve a public interest. In Egypt, administrative contracts are governed by Law No. 182 of the year 2018 for Regulating Contracts concluded by Public Entities, which has been promulgated in October 2018. This Law includes several mandatory rules, which will govern over any conditions in the construction contract.

The FIDIC Red Book 1999 is widely used in Egypt and the Middle East in private sector and is currently also being utilized by governmental bodies. However, some contractors are not aware of the major deviations …

Development Of Self-Stressing Ultra High-Performance Concrete Using Expansive Chemical Admixtures, Lane Edwards

Graduate Theses and Dissertations

This study investigated the effects of expansive chemical admixtures on ultra-high performance concrete (UHPC) and self-stressing mechanisms. A literature review was performed to determine different types of expansive admixtures for feasibility of the self-prestressing concept. Ultimately it was decided that type-k cement, made by combining Komponent admixture with conventional UHPC, was the most suitable option due to its effects on wet and hardened concrete properties. Mix designs with varying amounts of Komponent were developed to test the effects the admixture had on various properties. Tested properties included, workability, compressive strength, expansion, short-term shrinkage, long-term shrinkage, and developed prestress. The development …

Systematic Literature Review Of Roof Systems On Energy Efficiency Of A Building To Support An Ideal Study Framework, Ayushi Raj Dua

All Theses

A sustainable building envelope is a crucial element to build energy efficient structures that contribute towards sustainable communities. The demand for sustainable building envelopes has grown in response to a growing emphasis on sustainable living. The roofing system is an important component of a sustainable building envelope because it influences the building's energy consumption and indoor comfort levels. The current study focuses on roofing systems and associated solar reflectance and albedo values to document the impact on energy efficiency via cooling/heating energy usage, dollar savings and temperature (ambient and surface) reductions due to the roofing systems. Additionally, the study focuses …

Floating Offshore Wind Turbine Project, Courtney Huitt, Cormack Williams

Civil and Environmental Engineering

Offshore wind is a developing industry in the Central Coast with the advent of the future offshore wind project planned off the north coast of San Luis Obispo County. This senior design project aligns with the recently leased wind energy project as a detailed study on the structural design, geotechnical design, and construction of a single 14 MW floating offshore wind turbine (FOWT) located 40 km NW of Morro Bay (NOAA buoy 46028). A preliminary design of a spar FOWT is presented in this project as a solution to the rapidly increasing water depth off the coast of Morro Bay, …

Reducing The Vulnerability Of Electric Power Infrastructure Against Natural Disasters By Promoting Distributed Generation, Gasser G. Ali, Islam H. El-Adaway, Charles Sims, J. Scott Holladay, Chien Fei Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Natural disasters cause significant damage to the electrical power infrastructure every year. Therefore, there is a crucial need to reduce the vulnerability of the electric power grid against natural disasters. Distributed generation (DG) represents small-scale decentralized power generation that can help reduce the vulnerability of the grid, among many other benefits. Examples of DG include small-scale photo-voltaic (PV) systems. Accordingly, the goal of this paper is to investigate the benefits of DG in reducing the vulnerability of the electric power infrastructure by mitigating against the impact of natural disasters on transmission lines. This was achieved by developing a complex system-of-systems …

Building Services Engineering May/June 2023

Building Services Engineering

No abstract provided.

Experimental Investigation Of The Self-Healing Potential Of Bacteria For Sustainable Concrete Structures, Pitiporn Asvapathanagul, Simone Galano, Andrea Calabrese, Mehran Rahmani, Maggie Ly, Daniela Flores, Michael Hernandez, Nicholas Banuelos

Mineta Transportation Institute

Although concrete is the most widely used building material in the world, its limited tensile strength makes cracking a common phenomenon in concrete elements. This study investigates the potential of autonomous self-healing as an eco-friendly and lowcost method to increase the durability of concrete. The crack-healing potential of different types of high-alkaline-tolerant bacteria or calcite-precipitation microorganisms is investigated. High-alkaline-tolerant bacteria and calcite-precipitation microorganisms were used to retrofit lab-fractured concrete samples. The samples healed with each of these bacteria groups were cast and tested under compressive load up to failure to measure the compressive strength of the concrete samples. The outcomes …

Personal Protective Equipment Usage And Injury Type, Nathan Giannini

Construction Management

Workers in the construction industry have many injuries both minor and life-altering. The industry suffers from injuries of all kinds such as falls, electrocution, and being struck by flying objects. To protect against this, workers wear certain types of personal protective equipment (PPE) on construction sites as a last line of defense. The equipment available such as hard hats, safety glasses, gloves, respirators, and hearing protection either protects against acute injuries (those that occur instantly) or chronic injuries (those that occur over time). This study investigates whether the type of injury that PPE protects against, acute or chronic, affects the …

Designing A Work-Life Balance Learning Module For Cal Poly Construction Management Department, Alex Jones

Construction Management

The construction industry is known to create a highly stressful work environment given its unpredictability and mental/time demanding nature, which creates challenges for professionals to maintain a healthy work-life balance. This senior project aims to research and identify the key areas that foster this stress and propose a learning module for the Cal Poly Construction Management Department to implement into class curriculum. Having this learning module taught to students will raise awareness of the topic for future industry professionals and equip them with the tools to maintain a healthy equilibrium between their work demands and personal life. The learning module …

An Introduction To Autocad For Beginners, Zoe L. Mahaney

Construction Management

This paper aims to outline the process of developing and creating an online instructional video tutorial for beginner level individuals who hope to learn and utilize AutoCAD software. AutoCAD, developed by Autodesk, is a computer-aided design software that provides users with the ability to create and edit digital 2D and 3D designs, which is more efficient than traditional hand-drawn models. The main objective of this project is to provide the public with access to learning and navigating AutoCAD software on their own, for personal gain. Construction Management students at Cal Poly have the opportunity to learn and use AutoCAD as …

A Step-By-Step Guide To Identify The Most Reliable Inventory Management System For Small Businesses Using Discrete Event Simulation And Pros And Cons Analysis: A Case Study At Camid-Florida Tech, Djalma Batista Oliveira Filho

Theses and Dissertations

According to the Department of Labor Statistics (2022), 20.6% of small businesses fail in their first year of operation, 42.6% fail after five years, and over 62.6% fail by their tenth year. One factor that can affect continued viability is the lack of knowledge and experience among small and medium-sized firms in inventory management. Despite the fact that inventory control is one of these businesses' most ignored management responsibilities, the expense of procuring inventory often accounts for a considerable portion of their budget. Due to poor inventory management or an inability to appropriately supervise their inventory, small firms may have …

Effects Of Process Parameters On The Dimensional Accuracy Of Fused Deposition Modeled Parts, Ethan Eugene Bair

Theses and Dissertations

Fused deposition modelling (FDM) is one of the most common additive manufacturing techniques used with applications ranging from rapid prototyping at a professional scale to simple part creation at a hobbyist scale. FDM printing has very little in terms of information based on how accurate printed parts can be. This issue, which is common amongst many different types of additive manufacturing techniques, is something that has not been studied in FDM printed parts in high volumes. Research based on the effects of process parameters on mechanical properties has been conducted in high proportions. This study focused on FDM machines using …