Durability of Traffic Paint on Portland Cement Concrete Pavements

Performance of a series of transverse lines applied to a relatively new concrete pavement, utilizing primes and pretreatments, is reported. The report includes descriptions of the location of test lines and types of paint and pretreatments, performance histories, and analysis of results. Chlorinated rubber, epoxy, and urethane paints were the most durable. Neither pretreatment nor the use of primes significantly increased durability

Voidless Concrete Mixtures for Bridge Decks

The purpose of this study was to modify concrete mix-design formulas to supplant all water over and above that needed for hydration with a non-evaporable material -- thus producing a no-void concrete. It was adjudged that a water-cement ratio of 0.244 would be practical for hydration of the cement. Several polymeric materials, asphalts, and oils were used to replace the excess mixing water. Success was achieved using two latexes and one epoxy. The use of these materials in concrete resulted in improved strength, reduction of air voids and permeability, and enhancement of resistance to corrosive chloride salts

Expansive Limestone Aggregate in a Concrete Pavement

Recurrent blowups and surface cracking are common symptoms of distress in concrete pavements. Premature appearance of distress symptoms is alarming because the materials used in the concrete become suspect. Criteria for design, quality of materials, and construction are necessarily re-evaluated. Indeed, a dutiful effort to discover the cause(s) and to provide future safeguards is reasonably expected. The analysis of causative factors besetting I 65-1(13)13 was complicated by an intuitive notion that blowups and surface cracks might be separate and independent problems. The crack pattern resembled the configuration of the wire mesh -- which was vibrated into position after the concrete was spread and screeded. The blowups are, as the evidence presented here will show, attributable to expansive forces arising from a limestone aggregate which now has been identified with specific ledges in the source quarry. The nature of this aggregate was such that its deleterious or expansive character would not have been detected by the specification tests and routine safeguards then in effect. However, insights extending beyond specification requirements surely would have made the ledges suspect had they been brought to bear in this instance. This report includes a relevant history of the project and results from the several investigative tests undertaken

Evaluation of Cored Specimens from Timber Caisson Beneath Pier No. 2 of the US 25 Bridge over the Ohio River between Covington and Cincinnati

Pier No. 2 of the former C&O Bridge at Covington is off-shore from the Kentucky side of the Ohio River. It was built in 1887. In 1927, this pier was extended downstream to support a new railroad bridge. The other three piers remained independent. The original structure was then converted to highway use and was purchased by the Commonwealth of Kentucky in 1937. In 1968, an engineering analysis of the superstructure indicated critical deficiencies in terms of safety factors , and the bridge was closed to all traffic. Subsequently, various plans for reconstruction came under consideration. Of greatest significance here is the consideration toward re-use of Pier No. 2 – jointly with a new highway bridge and the existing railroad bridge. Cost estimates appeared persuasive; the structural feasibility remained dependent upon the integrity of the pier -- more specifically, the worthiness of the masonry, concrete, and the underlying timber caisson. Prior to removal of the steel superstructure (fall of 1970), vertical cores were extracted from Pier No. 2 for evaluation. This report concerns the evaluation of specimens of wood from the timber caisson. The substructure construction was described by Wm. H. Burr, in the Transactions of the American Society of Civil Engineers, Vol. XXIII, 1890; a copy is appended hereto for convenient reference; Plate XIII, therein, is most pertinent

Relative contributions of solid skeleton visco-plasticity and water viscosity to the poro-mechanics behavior of callovo-oxfordian claystone

The Callovo-Oxfordian claystone is a saturated porous medium. Its transfer properties, including its low permeability [16] make it an interesting candidate for underground radioactive waste disposal. The drained tests performed on the claystone, collected by ANDRA1 from samples at 500 meters depth [16, 9], exhibits a damageable visco-elasto-plastic behavior. This viscous behavior includes both the viscosity of the skeleton and the water. In existing models [5, 6, 11, 1], the creep phenomena are attributed either to the water permeability, to the skeleton visco-plasticity or sometimes both [13]. In a first step, a simplified analysis is proposed to understand the contribution of each phenomenon with respect to the consolidation time. This study indicates that the apparent characteristic time is the sum of those related to the skeleton and water permeability. To handle both non-linear and viscous phenomena, the damage law [15], coupled with the basic creep model [14] is used to characterize the solid skeleton of the claystone. The fluid behavior is integrated with the poro-mechanical model [7] implemented in the finite element code CAST3M [4]. The proposed model (visco-elastic damageable skeleton + saturating fluid) is used to simulate an excavation from the ANDRA underground laboratory (located in Bure–France). This application allows the understanding of how both viscous phenomena combine at each step of the calculation. Just after the excavation, water overpressure decreases near the gallery approaching zero due to the damage and then increases the permeability. The viscosity is then controlled by the solid skeleton creep rates. Later, the redistribution of hydraulic pressure is of more importance and permeability again plays a major role

Machine Learning Data Suitability and Performance Testing Using Fault Injection Testing Framework

Creating resilient machine learning (ML) systems has become necessary to ensure production-ready ML systems that acquire user confidence seamlessly. The quality of the input data and the model highly influence the successful end-to-end testing in data-sensitive systems. However, the testing approaches of input data are not as systematic and are few compared to model testing. To address this gap, this paper presents the Fault Injection for Undesirable Learning in input Data (FIUL-Data) testing framework that tests the resilience of ML models to multiple intentionally-triggered data faults. Data mutators explore vulnerabilities of ML systems against the effects of different fault injections. The proposed framework is designed based on three main ideas: The mutators are not random; one data mutator is applied at an instance of time, and the selected ML models are optimized beforehand. This paper evaluates the FIUL-Data framework using data from analytical chemistry, comprising retention time measurements of anti-sense oligonucleotide. Empirical evaluation is carried out in a two-step process in which the responses of selected ML models to data mutation are analyzed individually and then compared with each other. The results show that the FIUL-Data framework allows the evaluation of the resilience of ML models. In most experiments cases, ML models show higher resilience at larger training datasets, where gradient boost performed better than support vector regression in smaller training sets. Overall, the mean squared error metric is useful in evaluating the resilience of models due to its higher sensitivity to data mutation.Comment: 18 page

Supersymmetric Sum Rules for Electromagnetic Multipoles

We derive model independent, non-perturbative supersymmetric sum rules for the magnetic and electric multipole moments of any theory with N=1 supersymmetry. We find that in any irreducible N=1 supermultiplet the diagonal matrix elements of the l-multipole moments are completely fixed in terms of their off-diagonal matrix elements and the diagonal (l-1)-multipole moments.Comment: 10 pages, plain Te