BIM-based benchmarking system for healthcare projects: Feasibility study and functional requirements

While project benchmarking based on key performance indicators is regarded as a crucial technique for mature project delivery in the construction industry, incorporating it into an organization's routine is a cumbersome and time-consuming endeavor as it entails considerable time and human efforts for collecting and providing project information, and validating the quality of collected data. To overcome this challenge, this paper introduces an approach that leverages Building Information Modeling (BIM), which allows for a more streamlined benchmarking process. The approach presented in this paper focuses on healthcare projects which have been benchmarked using a comprehensive set of cost, schedule, dimension, and planning performance metrics through a mature sector-specific benchmarking program at Construction Industry Institute (CII). As an initial step in the formulation of such a tool, this paper investigates the potential of leveraging BIM for benchmarking through close scrutiny of contents embedded in real-world models collected from six healthcare projects. Functional requirements were, then, established to realize a BIM-based benchmarking tool for healthcare projects by developing conceptual process flow, use cases, and data flow diagrams. The requirements are further illustrated in mock-ups of a prototype system.     

盾构穿越桥梁桩基的托换及除桩施工技术研究

在上海轨道交通10号线溧阳路站~曲阳路站区间隧道的施工中,当盾构在推进至四平路沙泾港桥位置时,将不得不从桥梁的桩基中穿过。由于桩的入土深度已经贯穿了整个隧道断面,导致必须对桩基进行拔除或切断等处理。由于四平路为上海市交通干道之一,交通量大且地位重要,不允许使该桥所承担的交通量受到影响。同时,该桥周围为密集住宅小区,施工空间有限,因此工程风险较高、难度很大。为了保证施工中旧桥的功能发挥的同时,去除影响盾构向前推进的障碍物,本工程采取扩大板式基础托换及除桩工法,以此做到社会影响小、施工周期缩短、降低造价并达到优质工程的目的。     

Shear capacity of masonry walls externally strengthened by a cement-based composite material: An experimental campaign

Composite materials are getting more and more common for strengthening existing members and structures; fiber-reinforced polymers (FRP) are widely used, while carbon-fiber-reinforced cement matrix (CFRCM) materials have been more recently proposed especially for strengthening masonry members. In the present paper, the results of an experimental campaign carried out on tuff-masonry walls strengthened in shear by a cement-based composite are reported and commented. The reinforced masonry walls failed after loss of adhesion between the strengthening layer and the masonry substrate. Comparisons between the experimental results and some analytical formulations available in the scientific literature for determining shear resistance of strengthened masonry walls are finally proposed. Huge variability can be observed by applying those alternative formulations which are not able to reproduce the premature nature of the observed failure mode. Consequently, the present study is a thorough experimental report which can be useful for developing and validating more refined theoretical models for describing the ultimate behaviour of masonry walls externally strengthened by FRP.     

Compressive strength and degree of reaction of biomass- and fly ash-based geopolymer

Rice husk and bark ash (RHBA) was used as a rich SiO₂ source to partially replace fly ash in making geopolymer. Consequently, the SiO₂/Al₂O₃ ratio was extended to the wide range of 4.03–1035. Compressive strength, degree of reaction, and microstructure of the geopolymers were investigated to observe the effect of SiO₂/Al₂O₃ ratio. Results revealed that the optimum SiO₂/Al₂O₃ ratio to obtain the highest compressive strength was 15.9. Fly ash was more reactive than RHBA. It was also shown that not only the reactivity of the source materials but also the quality of the matrix contributed to the enhancement of compressive strength of the geopolymer paste.     

Effect of fiber loading on the properties of treated cellulose fiber-reinforced phenolic composites

The effect of fiber loading on the properties of treated cellulose fiber-reinforced phenolic composites was evaluated. Alkali treatment of the fibers and reaction with organosilanes as coupling agents were applied to improve fiber–matrix adhesion. Fiber loadings of 1, 3, 5, and 7 wt% were incorporated to the phenolic matrix and tensile, flexural, morphological and thermal properties of the resulting composites were studied. In general, mechanical properties of the composites showed a maximum at 3% of fiber loading and a uniform distribution of the fibers in such composites was observed. Silane treatment of the fibers provided derived composites with the best thermal and mechanical properties. Meanwhile, NaOH treatment improved thermal and flexural properties, but reduced tensile properties of the materials. Therefore, the phenolic composite containing 3% of silane treated cellulose fiber was selected as the material with optimal properties.     

Numerical Cracking and Debonding Analysis of RC Beams Reinforced with FRP Sheet

Bonding a fiber reinforced polymer (FRP) sheet to the tension-side surface of reinforced concrete (RC) structures is often performed to upgrade the flexural capacity and stiffness. Except for upper concrete crushing, FRP sheet reinforcing RC structure may fail in sheet rupture, sheet peeloff failure due to opening of a critical diagonal crack, or concrete cover delamination failure from the sheet end. Accompanying the occurrence of these failure modes, reinforcing effects of the FRP sheet will be lost and load-carrying capacity of the RC structures will be decreased suddenly. This study is devoted to developing a numerical analysis method by using a three-dimensional elasto-plastic finite element method to simulate the load-carrying capacity of RC beams failed in the FRP sheet peeloff mode. Here, the discrete crack approach was employed to consider geometrical discontinuities such as opening of cracks, slipping of rebar, and debonding of the FRP sheet. Comparisons between analytical and experimental results confirm that the proposed numerical analysis method is appropriate for estimating the load-carrying capacity and failure behavior of RC beams flexurally reinforced with a FRP sheet.     

Flow Intensity Parameter in Pier Scour Experiments

Technical note discusses a detailed approach to dimensional analysis for the bridge pier scour phenomenon and the introduction of flow intensity. It demonstrates the dependence of critical upstream velocity on the rest of the parameters describing the process and its implications on dimensional analysis. Assuming that the viscous effects are negligible in the local scour phenomenon, it is concluded that the flow intensity of the approaching undisturbed flow is not an adequate parameter to describe the process in usual laboratory conditions. A new proposal is established.     

Finite element modelling of CFRP jacketed CFST members under flexural loading

In this era, using concrete filled steel tubular (CFST) members has become very popular in the construction industry; at the same time, ageing of structures and deterioration of members are often reported. Therefore, actions like implementing strengthening techniques with the new materials become essential to combat this problem. Due to their in-service and superior mechanical properties, carbon fibre reinforced polymer (CFRP) composites make an excellent candidate after upgrading. The aim of this study is to experimentally investigate the suitability of CFRP in strengthening of CFST members under flexure. Among eighteen beams, nine beams were strengthened by full wrapping (fibre bonded at the bottom throughout the entire length of beam) and the remaining nine beams were strengthened by partial wrapping (fibre bonded in-between loading points at the bottom). The effect of CFRP layers on the moment carrying capacity of CFST beams was investigated. Also a nonlinear finite element model was developed using the software ANSYS 12.0, to validate the analytical results such as load–deformation and the corresponding failure modes. The experimental results revealed that beams strengthened by partial wrapping failed by delamination of fibre, even before attaining the ultimate load of control beam but the beams strengthened by full wrapping exhibited more enhancements in moment carrying capacity and stiffness. From the numerical simulation and experiments, it is suggested that if any appropriate anchorages are provided in partial wrapping scheme to avoid delamination of fibre, then it will be turned into a fine and economical method for strengthening of CFST members.