Compressive Strength of Concrete Cylinders by Different Preparation Methods: Sulphur, Neoprene Pads and Grinding

The purpose of this evaluation is to compare the effects of four types of cylinder preparation methods prior to compressive strength testing in accordance to ASTM C 39

Evaluation of Nebraska’s Aggregate Reactivity by the Miniature Concrete Prism Test Method – AASHTO T380

The evaluation of nine different aggregates shows the viability of the T380 test method as an alternative to the standard C1293 test method. The T380 assesses the Alkali-Silica Reaction potential of aggregates with the same reliability as C1293 and correlates well with the C1293 test method. Results are obtained within 56 days by T380 compared to 365 days required by C1293. The T380 method at 56 days appears to characterize the aggregate reactivity similarly to C1293 for all the aggregates evaluated in this study. Therefore, T380 will be part of the Department test method for approval of interground/blended cements along with the ASTM C1567-Standard Test Method for Determining the Potential Alkali-Silica Reactivity of Combinations of Cementitious Materials and Aggregate. The Department has changed the specification for approving IP or IT cements to allow the use of T380 after the Department has completed the test method C1567. Per the specification, the mortar bars shall not exceed 0.10% expansion at 28 days while performing C1567. If the expansion is greater than 0.10% at 28 days while performing C1567, then the interground/blended cements shall be tested in accordance with AASHTO T380 using fine aggregate from an approved Platte River Valley and/or Elkhorn River aggregate source with an expansion not greater than 0.02% at 56 days

Banking conditions in the 12th District: Has the recovery taken hold?

The recession officially ended in June, 2009, yet more than a year later, many banks throughout the nation are struggling to recover from the downturn. This is especially pronounced in the 12th District. This article addresses some of the issues that contributed to the still-prevalent banking crisis, discusses emerging signs of improving banking conditions, and considers the headwinds that the banking industry will continue to face as it mounts its recovery.Banks and banking ; Federal Reserve District, 12th

Effect of Moisture Condition on Concrete Core Strengths

The main purpose of this study was to determine if there would be any major differences between curing methods of cores taken for acceptance testing from a highway slab on a project. The comparison provided data to determine the effect of the moisture gradients created by these different curing treatments on core strength and core permeability. The strengths were measured of moist cured cores and sealed plastic bag cured cores from the day cores were obtained (14, 21 and 26 days) until they reached 28 days. Permeability was also measured at 26, 28 and 32 days. According to ASTM C42, it is current practice to allow the cores to remain in a sealed condition with a plastic bag or non-absorbent containers for at least 5 days prior to testing unless otherwise specified by the engineer. Currently, Nebraska Department of Transportation (NDOT) follows the ASTM C42 with the exception that all cores obtained for compressive strength testing must be delivered to the PCC Lab in a sealed bag, un-bagged and stored immediately in a moist cure room until the required 28-day testing. The findings from this study show no significant difference in strength nor in permeability between curing concrete core samples in bags versus storing them in a moist room

La Pittura e la scultura dalle origini al Novecento

L'arte della Sardegna settentrionale rispecchia l'influsso delle dominazioni che, succedendosi nei secoli nel possesso dell'isola, condizionarono in parte lo sviluppo di espressioni autoctone. In questo studio, si esamina la pittura e la scultura dal Duecento sino al Novecento

Process report of stage II : The People's Committee for a Better Neighbourhood Inc.

22 leaves

The blurring of Belgium’s security: deliberate or unintended? Egmont Paper 95 June 2017

Since January 2015, the Belgian public has grown accustomed to the presence of soldiers in the streets, following terrorist threats and attacks. Their misson has been prolonged each month by the government and has now become “permanently temporary”. As a result, Defence has become the most popular public service in Belgium! Nevertheless, Wally Struys expresses serious doubts about the cost-efficiency of this mission in the Belgian cities, considering the mission statement of Defence and its involvement in external operations

Spin Sum Rules and Polarizabilities

The Gerasimov-Drell-Hearn sum rule and related dispersive integrals connect real and virtual Compton scattering to inclusive photo- and electroproduction. Being based on universal principles as causality, unitarity, and gauge invariance, these relations provide a unique testing ground to study the internal degrees of freedom that hold a system together. The present contribution reviews the spin-dependent sum rules and cross sections of the nucleon. At small momentum transfer, the data sample information on the long range phenomena (Goldstone bosons and collective resonances), whereas the primary degrees of freedom (quarks and gluons) become visible at large momentum transfer (short distance). The rich body of new data covers a wide range of phenomena from coherent to incoherent processes, and from the generalized spin polarizabilities on the low-energy side to higher twist effects in deep inelastic scattering.Comment: 15 pages, 7 figures, Proc. of Spin structure at long distance, Newport News, Virginia, 200

Dual SCR chopper as a motor controller for an electric car

Despite recent advances in solid-state controls for electric cars, chopper-induced problems still exist: commutation and ac losses are significantly high, the chopping action induces losses within the power source, and large ripple components in the chopper output cause increased rms losses at the motor. The author's dual chopper, two conventional choppers in parallel, reduces these problems. The duty cycle generated by the firing circuit is feedback controlled so that the load current remains proportional to control output. The dual chopper operates in a three-in-one system: in the first mode, the batteries charge at high rates; the second mode controls the amount of power flowing from battery to motor; and in the third or regenerative braking mode, the chopper transfers energy from the motor to the battery