Effect of Aramid Fibers on Balanced Mix Design of Asphalt Concrete

Fiber-reinforced asphalt concrete (FRAC) was tested using limestone, PG 64-22 binder, and 20% reclaimed asphalt pavement (RAP). After mixing fibers with different lengths and dosages, they were extracted and recovered to evaluate their dispersion in the FRAC. The uniaxial fatigue test, IDEAL CT test, and flow number test were performed on FRAC with different fiber lengths and asphalt contents. The balanced mix design (BMD) approach was then used to analyze the uniaxial and flow number test results in order to evaluate the effect of aramid fibers on fatigue and rutting resistance of the pavement. The dispersion test showed that the 19 mm and 10 mm aramid fibers at a dosage rate of 0.5 g/kg provided the best dispersion. The 19 mm fibers showed better performance test results than the 10 mm and 38 mm fibers. The BMD approach provided ranges of asphalt contents to produce mixes with certain resistances to fatigue and rutting. The BMD approach also demonstrated the effect of fibers with different lengths on increasing the resistance to fatigue and rutting. The study concluded that the 19 mm fibers with a dosage of 0.5 g/kg produce best results. The BMD approach is a good tool that can be used to refine the mix ingredients, including additives such as fibers, in order to optimize pavement resistance to various distresses such as fatigue cracking and rutting.

Characteristic-free test ideals

Tight closure test ideals have been central to the classification of singularities in rings of characteristic p > 0 p>0 , and via reduction to characteristic p > 0 p>0 , in equal characteristic 0 as well. Their properties and applications have been described by Schwede and Tucker [Progress in commutative algebra 2, Walter de Gruyter, Berlin, 2012]. In this paper, we extend the notion of a test ideal to arbitrary closure operations, particularly those coming from big Cohen-Macaulay modules and algebras, and prove that it shares key properties of tight closure test ideals. Our main results show how these test ideals can be used to give a characteristic-free classification of singularities, including a few specific results on the mixed characteristic case. We also compute examples of these test ideals.

Comprehensive Study about Effect of Basalt Fiber, Gradation, Nominal Maximum Aggregate Size and Asphalt on the Anti-Cracking Ability of Asphalt Mixtures

There are many parameters that could affect the properties of asphalt mixtures, such as the fiber additive, gradation type, nominal maximum aggregate size (NMAS), and asphalt. To evaluate the influence of these factors on the crack resistance of asphalt mixture, 10 different types of asphalt mixtures were prepared. The indirect tensile asphalt cracking test (IDEAL-CT) and semi-circle bending test (SCB) were adopted to test the anti-cracking ability of the test samples. The parameters of these two test results were also used to conduct the correlation analysis to find the correlation between different parameters, and scanning electron microscope (SEM) test was also used to analyze the micro cracks of asphalt mixture. The results showed that basalt fiber could further enhance the anti-cracking ability of asphalt mixture. Stone matrix asphalt (SMA) showed better anti-cracking performance than Superpave (SUP) asphalt mixtures. The increase in the nominal maximum aggregate size could decrease the anti-cracking ability of asphalt mixtures. Styrene-Butadiene-Styrene (SBS) modified asphalt could better reinforce the anti-cracking ability than pure asphalt. The CTindex of IDEAL-CT test and Flexibility index (FI) value of SCB test results showed better correlation. This paper has certain significance in guiding the design of asphalt mixtures having good crack resistance.

Laboratory Evaluation of Cracking Resistance for Asphalt Mixtures Modified with Nanoclay and Nanocellulose

Cracking failure is one of the major distress modes associated with asphalt pavement. Asphalt modification has been identified as an effective method to improve pavement performance. In this study, nanomaterials including bentonite and halloysite nanoclays and nanocellulose are added to PG 64-28 straight run asphalt binder for modification. The potential of these nanomaterials for improving the cracking performance of asphalt pavements at intermediate pavement service temperatures is investigated. Rheological evaluation is conducted using a dynamic shear rheometer (DSR), and the cracking resistance of the asphalt mixtures is determined through indirect tension asphalt cracking test (IDEAL-CT). A high shear mixer is used to disperse the nanomaterial in the asphalt and the field emission scanning electron microscope (FESEM) analysis shows a relatively good dispersion of the nanomaterials. Furthermore, the results of the IDEAL-CT show an improvement in cracking test index by as much as 47% to 114% through nanomaterial modification.

Image of an Ideal Future: Russians’ Normative Concepts of Authorities

The study analyses citizens’ normative concepts of authorities. The concepts serve as reference for comparing real authorities with their ideal counterpart. Images of ideal authorities have a complicated psychological structure connected with archetypes of national political culture. This defined the set of research instruments that include: focused interviews, semantic differential method, projective methods (associative test, method of unfinished sentences, drawing test “Ideal Authorities”), and some others. The sample included 450 respondents from 20 regions. The study has shown the following. Besides immediate reactions to the authorities’ decisions and particular events, political behavior and mentality are also determined by deeper factors connected with ideal representations, values and archetypes that serve as references for citizens in their evaluation of real authorities. Images of the future play the role of an action acceptor preempting and tuning people’s behavior in the present. The absolute majority of the respondents (86%) believe that authorities are an intrinsic part of our social design. This does not mean that real authorities are so attractive for them. But in some ideal future the overwhelming majority (74.9%) evaluate authorities positively. The author’s data show that in recent years normative representations of authorities have essentially transformed in Russia. Citizens revised their expectations from authorities. On the unconscious level of authorities’ perception, the need for love, respect and care about people dominates over material needs. Lack of this need’s satisfaction causes the growth of political distrust, absenteeism and escapism. A number of archetypical representations in the images of ideal authorities have been revealed; these representations – of an integral, indivisible and sacred nature of authorities – constitute the core of Russian mass political mentality. The respondents do not share the idea of division of power into different branches or levels and their checks and balances. Executive power dominates the legislative and judicial ones not only in the present but also in the image of the future. Opposition seems to be equally incompatible with our tradition and is seen as artificial and “fake”. This attitude also concerns many other concepts of contemporary official political discourse. They are formally recognized but on unconscious level are called into question. New “democratic” norms and values constitute the peripheral part of political mentality. This layer of normative representations of authorities includes the ideas of power separation, the competition of elite groups and parties, the multiparty system etc. Thus, the structure of the images of authorities looks very heterogeneous and mosaic. Traditional representations and images dominate in it, but new ones have already penetrated mass mentality and gained a foothold in it though our citizens cannot understand why they need these images. These peripheral representations in the case of a crisis can be replaced by deeper and more authentic mental structures.

BERNSTEIN–SATO POLYNOMIALS AND TEST MODULES IN POSITIVE CHARACTERISTIC

In analogy with the complex analytic case, Mustaţă constructed (a family of) Bernstein–Sato polynomials for the structure sheaf${\mathcal{O}}_{X}$and a hypersurface$(f=0)$in$X$, where$X$is a regular variety over an$F$-finite field of positive characteristic (see Mustaţă,Bernstein–Sato polynomials in positive characteristic, J. Algebra321(1) (2009), 128–151). He shows that the suitably interpreted zeros of his Bernstein–Sato polynomials correspond to the$F$-jumping numbers of the test ideal filtration${\it\tau}(X,f^{t})$. In the present paper we generalize Mustaţă’s construction replacing${\mathcal{O}}_{X}$by an arbitrary$F$-regular Cartier module$M$on$X$and show an analogous correspondence of the zeros of our Bernstein–Sato polynomials with the jumping numbers of the associated filtration of test modules${\it\tau}(M,f^{t})$provided that$f$is a nonzero divisor on$M$.

A dual to tight closure theory

We introduce an operation on modules over anF-finite ring of characteristicp. We call this operationtight interior. While it exists more generally, in some cases this operation is equivalent to the Matlis dual of tight closure. Moreover, the interior of the ring itself is simply the big test ideal. We directly prove, without appeal to tight closure, results analogous to persistence, colon capturing, and working modulo minimal primes, and we begin to develop a theory dual to phantom homology. Using our dual notion of persistence, we obtain new and interesting transformation rules for tight interiors, and so in particular for the test ideal. Using our theory of phantom homology, we prove a vanishing theorem for maps of Ext. We also compare our theory with Blickle’s notion of Cartier modules, and in the process we prove new existence results for Blickle’s test submodule. Finally, we apply the theory we developed to the study of test ideals in nonnormal rings, proving that the finitistic test ideal coincides with the big test ideal in some cases.

A dual to tight closure theory

We introduce an operation on modules over anF-finite ring of characteristicp. We call this operationtight interior. While it exists more generally, in some cases this operation is equivalent to the Matlis dual of tight closure. Moreover, the interior of the ring itself is simply the big test ideal. We directly prove, without appeal to tight closure, results analogous to persistence, colon capturing, and working modulo minimal primes, and we begin to develop a theory dual to phantom homology. Using our dual notion of persistence, we obtain new and interesting transformation rules for tight interiors, and so in particular for the test ideal. Using our theory of phantom homology, we prove a vanishing theorem for maps of Ext. We also compare our theory with Blickle’s notion of Cartier modules, and in the process we prove new existence results for Blickle’s test submodule. Finally, we apply the theory we developed to the study of test ideals in nonnormal rings, proving that the finitistic test ideal coincides with the big test ideal in some cases.

Test Ideals Vs. Multiplier Ideals

The generalized test ideals introduced in [HY] are related to multiplier ideals via reduction to characteristic p. In addition, they satisfy many of the subtle properties of the multiplier ideals, which in characteristic zero follow via vanishing theorems. In this note we give several examples to emphasize the different behavior of test ideals and multiplier ideals. Our main result is that every ideal in an F-finite regular local ring can be written as a generalized test ideal. We also prove the semicontinuity of F-pure thresholds (though the analogue of the Generic Restriction Theorem for multiplier ideals does not hold).