A Study of the Correlation Between Static and Dynamic Modulus of Elasticity on Different Concrete Mixes

This study is to determine the relationship between the Static Modulus of Elasticity and the Dynamic Modulus of Elasticity in various concrete mixes. The Static Loading Test was used to measure the strains associated with applied stresses on cylindrical concrete specimens to determine the Static Modulus. An Ultrasonic Pulse Wave Velocity (UPV) technique was utilized to measure the travel time of pulse waves propagating through rectangular prism specimens. The travel times were used to compute the Dynamic Modulus of Elasticity. An Impact Hammer measuring device was also used to measure resonance frequencies of vibrations in rectangular prisms, which also correlate to the Dynamic Modulus.;Four different concrete mixes were cast and each underwent the testing at 1, 3, 7, 14, and 28 days. The four concrete mixes were a 50% Slag mix, a 30% Flyash mix, an Ordinary Portland Cement (OPC) mix, and a Self-Consolidating Concrete (SCC) mix. The relationships between different calculated moduli values were plotted against each other to determine the correlation between them. Empirical relationships based on these values were then determined. The Static Modulus values were also computed using ACI 318 equations, and were compared to the measured Static Modulus values.;The results show that the Dynamic Modulus of Elasticity is higher than the Static Modulus of Elasticity for each concrete mix. The Dynamic Modulus obtained from UPV resulted in the highest values, while the Static Modulus was the lowest at all ages. The relationship between the Static and Dynamic Modulus is linear. The Dynamic Modulus from UPV and Vibration methods also exhibits a linear relationship. Empirical equations were developed to estimate the Modulus of Elasticity at different ages.;SCC had a much higher compressive strength compared to other concrete mixes. The use of ACI 318 equations to estimate Young\u27s Modulus from 28-day compressive strength yielded conservative values as compared to the measured Static Modulus values

Retrofitting a water quality control structure to maximize pollutant removal efficiency for an existing wetland

2014 Spring.Includes bibliographical references.An existing seven acre wetland captures stormwater runoff from a 505 acre watershed located in Fort Collins, CO. The wetland has shown measurable pollutant removal with its current outlet design, but the pollutant removal efficiency could be increased through the installation of a water quality control structure (WQCS). The wetland is bounded by an adjacent park, stream, bike path, and building limiting water quality improvement options. Thus, the wetland dimensions cannot be altered. The objective of this project is to design a water quality control structure that would maximize pollutant removal efficiency and the mass of total suspended solids (TSS) removed in the wetland without causing additional flooding at the site and adversely affecting the adjacent properties. An additional objective of this project was to develop a method to calculate the hydraulic retention time (HRT) for a stormwater wetland. EPA's Stormwater Management Model Version 5 was used to model the existing conditions and various proposed WQCS drawdown times. The modeled drawdown times ranged from 2 hours to 72 hours. Continuous simulation modeling was used because the wetland volume could not be adjusted to contain the water quality capture volume. It was assumed that all stormwater runoff entering the wetland was captured and treated. Using the model generated volume, depth, and flow data, the non-steady state hydraulic retention times and hydraulic loading rates (HLR) were calculated for each drawdown time analyzed. The k-C* method developed by Kadlec and Knight (1996) and measured data from the wetland were used to calculate the pollutant removal efficiency and the total annual TSS removed. The results indicate that a drawdown time of 30 hours will provide the best removal efficiency while considering the site constraints. The installation of the WQCS will have an HRT of approximately 14 hrs and increase the removal efficiency by 14.2% and the total annual TSS removed by 31,100 lbs from existing conditions. Furthermore, the addition of the WCQS will only increase the maximum flooding depth and duration at the overflow locations by a maximum of 0.02 ft and 0.2 hrs, respectively, for the 100yr storm event. For the 2yr storm event, the addition of the WCQS will only increase the maximum flooding depth and duration at the overflow locations by a maximum of 0.01 ft and 0.1 hrs, respectively. The depth of water in the wetland, for both storm events analyzed, will not exceed the wetlands embankment at any location besides the overflow locations. At brimful conditions, the detained runoff water remains in the main channel and permanent pool areas of the wetland. The methods developed in this project can be used to retrofit an existing wetland with a WQCS that would maximize removal efficiency while considering site constraints

Male parole

Il turpiloquio è un fenomeno presente fin dalle più antiche attestazioni della lingua italiana, oltre che del linguaggio in generale. Nell'ultimo mezzo secolo, tuttavia, la pornolalia e la coprolalia sono diventate alla moda, creando le basi per quella "volgare eloquenza" che circola ampiamente nei media e nel dibattito politico

Natura giuridica dei corsi d’acqua minori

Estratto da : Rivista Giuridica di Salerno, a. IV., fasc.

Scrittura a mano armata. Pragmatica multimodale del messaggio minatorio

Il messaggio minatorio finalizzato all’estorsione mira a suscitare il panico nel destinatario per indurlo ad accettare le richieste avanzate dai banditi. Il terrorismo psicologico è esercitato in vari modi: a volte basta una raccomandazione bonaria accompagnata dal nome del famigerato malfattore; in altri casi si fa leva sulla minaccia esplicita alla persona, ai familiari e ai suoi beni, oppure si avverte di aver compiuto piccoli danni dimostrativi della capacità di nuocere. In alcune lettere di ricatto inedite scritte a Girgenti nel primo Novecento la violenza aggressiva del testo è accentuata da impressionanti disegni intimidatori

L'«esigenza del metodo». La critica di Ettore Lombardo Pellegrino all'idealismo giuridico

Through the critical analysis of contemporary methodologies in the field of public law, Ettore Lombardo Pellegrino finds out their common basic flaw in idealism. All currents of legal thought during the Eighteen’s century inherit, by the ancient and medieval political philosophy, the individualistic premise, a process from which constitutional theories are not given appropriate consideration to the “facts”. But the realistic analysis appears to be the only effective in the recognition of the democratic process

Il Mediator Epistularius nella pratica Amalfitana nel sec. 12. : memoria letta all'accademia di scienze morali e politiche della società reale di Napoli

Estratto dal volume LVIII degli Atti dell'Accademia di scienze morali e politiche della Società reale di Napol

Un confronto sulla proporzionale: Francesco Ruffini e Gaspare Ambrosini

The essay provides an overview on the comparison between Francesco Ruffini and Gaspare Ambrosini. The jourists vaunt different opinions on the problem of proportional representation, with particolar reference to the parliamentary committees’ composition. Ruffini is concerned about social interests and deems that they should be represented in the High Chamber of Parliament. But, sticking to the jusformalistic theory, he still distinguishes representative and deliberative decision. Ambrosini is critical about Ruffini's separation between society and institutions. In his analysis, after the introduction of the electoral proportional system, social interests are channeled in Parliament through political parties, who become the new subjects in policy