Mapping General System Characteristics to Non- Functional Requirements

The Function point analysis (FPA) method is the preferred scheme of estimation for project managers to determine the size, effort, schedule, resource loading and other such parameters. The FPA method by International Function Point Users Group (IFPUG) has captured the critical implementation features of an application through fourteen general system characteristics. However, Non- functional requirements (NFRs) such as functionality, reliability, efficiency, usability, maintainability, portability, etc. have not been included in the FPA estimation method. This paper discusses some of the NFRs and tries to determine a degree of influence for each of them. An attempt to factor the NFRs into estimation has been made. This approach needs to be validated with data collection and analysis.Comment: 5 page

Towards the Development of Performance-Based Concrete Mixtures Made with Modern Cementitious Materials Using Thermodynamic Modeling

This thesis builds on a modeling tool that has been developed to link thermodynamic modeling and concrete performance. This tool is intended to predict the performance for modern concrete mixtures made with ordinary portland cement (OPC), conventional and novel supplementary cementitious materials (SCMs), and limestone (Ls). The first part of this thesis provides improvements to the pozzolanic reactivity test (PRT) used to quantify the reactivity of SCMs. The PRT is performed by mixing the SCM with an excess of calcium hydroxide (CH) and 0.9N KOH and reacting the mixture at 50°C for 10-days. The cumulative heat released (Q) and the CH consumed by the SCM are measured, and the value of reactivity is calculated by comparing the measured Q and CH consumed to theoretical values of Q and CH consumed by pure SiO2 and Al2O3 (obtained from thermodynamic modeling). First, the PRT is simplified to determine the reactivity using the measured Q alone by demonstrating using thermodynamic modeling that the well-defined bounds on the chemical compositions of standardized SCMs result in these SCMs having a relatively constant Q/CH consumed response in the PRT. Next, thermodynamic models are used to calculate the Q and CH consumed by SCMs that are combinations of SiO2, Al2O3, and CaO, which improves the PRT as it enables the user to more accurately quantify the reactivity of aluminous SCMs and expands the scope of the PRT to hydraulic SCMs. The reaction of CaO has the highest Q in the PRT (=1189 J/g), and the combination of 37%SiO2+63%Al2O3 has the lowest Q (=647 J/g). The addition of sulfates and carbonates is not recommended as it changes the reaction of Al2O3 in the PRT and makes the quantification of reactivity more difficult. The second part of this thesis shows the development of a pore partitioning model for concrete (PPMC) to predict the performance of OPC+SCM systems. The porosity and pore volumes are predicted to be within 2% of experimental measures, and the formation factor to within 13% for OPC and within 23% for OPC+20% fly ash systems. These predicted properties are used to estimate the service life of concrete exposed to freeze-thaw cycles and can aid in mixture design, e.g., replacing 20% of OPC with fly ash (of reactivity 40%) requires increasing the air-entrainment by 1%. This thesis also examines the partial replacement of clinker with Ls when SCMs are used to lower the carbon footprint of concrete. Simulations showed that SiO2 in the SCM does not change the porosity significantly and Al2O3 in the SCM reacts synergistically with the Ls to form carboaluminates that fill space and lower the porosity. The use of cement with up to 15% Ls is encouraged when Al2O3-rich SCMs are used. This thesis is a step forward in providing the tools required to predict the performance of concrete made with OPC+SCM+Ls binders and aid in proportioning concrete mixtures to have a lower carbon footprint. The model is used to predict concrete strength and durability properties (such as formation factor, time to freeze-thaw damage, resistance to salt damage) across a range of water-to-binder ratios (w/b), SCM replacement levels, and air contents. Using these predictions, a range of w/b, SCM content, and air contents where the concrete meets a set of predefined target performances is obtained, which allows for the optimal design of a concrete mixture. Finally, it is shown that the PPMC can be used to aid in concrete mixture design. This framework was validated by designing mixtures for three different applications (a bridge deck, a Midwest pavement, a foundation) using four SCMs. Except for one SCM, which caused workability issues due to rapid setting, all mixtures designed to meet the performance targets met the targets

A Literature-based Dataset Containing Statistical Compositions and Reactivities of Commercial and Novel Supplementary Cementitious Materials

This dataset contains the chemical composition and reactivities of commercially used SCMs such as silica fume, Class-F and Class-C fly ashes, slags, and calcined clays. The dataset also includes the chemical composition and reactivity (where available) for several SCMs that are currently not specified in standard specifications by ASTM or AASHTO such as fly ashes not conforming to ASTM C618, bottom ashes, and pumices. This dataset can be used (i) for the classification of SCMs based on their statistics (in terms of composition and reactivity), (ii) as an input for predicting the performance of cementitious systems made with SCMs using thermodynamic modeling, (iii) generating realistic compositional and reactivity data for cementitious materials using techniques such as Monte-Carlo method, and (iv) for studying the feasibility of the use of novel SCMs in concrete based on the predicted performance of concrete made with these SCMs.Keywords: Portland cement, cement, ordinary Portland cement, OPC, supplementary cementitious materials, SCM, statistics, pozzolanic reactivity, reactivity, silica Fume, fly ash, slag, calcined clay, pumice, off-spec SC

CALTRANS: Impact of the Use of Portland-Limestone Cement on Concrete Performance as Plain or Reinforced Material - Final Report

CALTRANS does not currently allow Portland-Limestone Cements (PLC) to replace Ordinary Portland Cement (OPC) in concrete. PLC has been proposed for consideration in CALTRANS specifications due to potential benefits in reducing greenhouse gas (GHG) emissions. This report outlines a comprehensive plan to provide both experimental and computational analysis results to address whether PLC may replace OPC without loss of mechanical and durability performance of concrete materials and mixtures specific to California. The objective of this study was to provide data for CALTRANS to make informed decisions on whether specification changes to permit use of PLC would be appropriate. Additionally, the research team was asked to assess the impact of added limestone (LS) powder as an alternative to using ASTM C 595/AASHTO M 240 cement