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This paper describes the findings of a study carried out for evaluating the performance of cast in situ concrete block pavements for low volume roads. Concrete is filled up into a formwork of cells 150 mm x 150 mm x 100 mm made tip of thin plastic sheets and compacted to form flexible interlocked concrete blocks. Details of a laboratory investigation on the proportioning of mixes and the evaluation of the strength of different mixes arc presented. Cast in situ block pavements were constructed and tested in an accelerated pavement test facility. It was found that the blocks became interlocked and thai the block pavement displayed a very little amount of rutting along the wheel path. A falling weight deflectometer test indicated that the equivalent elastic modulus of cast in situ concrete blocks was over 2,500 MPa. An example of pavement design using cast in situ concrete blocks is presented. DOI: 10.1061/(ASCE)0733-947X(2005)131:9(662) CE Database subject headings: Concrete blocks; Concrete pavements; Pavement design Tests; Elastic analysis.

The paper presents the details of various investigations conducted for the laboratory evaluation of the performance of crumb-rubber modified asphalt mixes. Crumb rubber (CR) obtained from discarded truck and bus tires was used to modify 80/100 penetration grade asphalt cement. Fatigue and permanent deformation characteristics, temperature and moisture susceptibility, and oxidative aging are some of the performance indicators of mixes evaluated. A static indentation test was adopted for assessing the relative permanent deformation characteristics of different mixes. Three aggregate gradations: (1) superpave; (2) gradation specified by the Ministry of Surface Transport, India for asphalt concrete; and (3) one gap gradation, were considered in the investigation. Compared to normal mixes, CR modified mixes were found to have improved fatigue and permanent deformation characteristics. They also showed lower temperature susceptibility and greater resistance to moisture damage compared to normal mixes. Superpave mixes gave better overall performance compared to the mixes having other aggregate gradations. CE Database subject headings: Rubber; Binders, materials; Asphalt mixes; Laboratory tests; Fatigue strength; Deformation.

This paper describes the findings of a study carried out for investigating the structural behaviour of different types of cell-filled pavements. The main objective of the present study is to investigate the behaviour of pavements constructed by filling the cells with (a) cement concrete (b) soil cement and (c) sand cement laid over two different types of sub-bases (moorum and soil cement). A formwork of cells of thin recycled plastic sheets was used to construct cell-filled pavements, which function as cast-in situ interlocked block pavements. A loaded truck was used to apply about 1500 load passes on test sections for the purpose of conditioning the pavement sections before structural evaluation. Surface deflections were measured using a falling weight deflectometer and resilient moduli of pavement layers were estimated from the measured deflections. A comparison of costs of different types of cell-filled pavements with those of traditional flexible and rigid pavements designed for low traffic volumes indicates that cell-filled pavements are cost-effective compared with conventional pavements, particularly in locations with scarcity of aggregates. [ABSTRACT FROM AUTHOR]

In the context of pavement evaluation, backcalculation is the process of estimation of elastic properties of pavement layers using measured structural responses. A number of backcalculation programs are available for estimating effective pavement layer moduli from surface deflections. Different optimization techniques have been used in the development of these backcalculation models. Genetic algorithm (GA) has been used successfully in the recent past for backcalculation of pavement layer moduli. Selection of appropriate GA parameters is important for the efficient performance of the GA-based algorithm. However, there are no general guidelines available at present for the selection of GA parameters. This paper presents a study conducted for the selection of optimal GA parameters to be adopted for backcalculation of pavement layer moduli. The parameters have been selected on the basis of the level of accuracy desired and the corresponding computational effort (CE). The performance of the GA-based program with the selected parameters was evaluated using some hypothetical and field problems. [ABSTRACT FROM AUTHOR]

In India, the aggregate gradation of bituminous mixes and acceptable limits of mix design parameters have evolved through experience in construction and performance, Emphasis, generally, is on the maximum attainable density and strength parameters. However, in view of the fact that pavement failure due to fatigue cracking is predominantly observed in bituminous toads in India, it is necessary to develop or revise suitable specifications for bituminous mixes so that the mixes have high fatigue strength while satisfying the Marshall stability requirement, The present work reports a comparative study of the engineering parameters of various bituminous mixes with aggregate gradations that are different from those recommended in the Ministry of Surface Transport (MOST) specifications for bituminous concrete (BC). New mix specifications for BC have been proposed in this paper, which showed better performance than the conventional gradation without compromising with the Marshall stability and other mix volumetric requirements. A model table is presented to show the economy in temps of reduction of design thickness of pavement compared to the conventional BC mix. [ABSTRACT FROM AUTHOR]

Features a study which described the results of an investigation for the development of a mechanistic design of bituminous pavements based on pavement performance data obtained from research projects in India. Evaluation of fatigue and elastic properties of pavement materials; Calibration of fatigue and rutting criteria; Development of computer program for pavement design; Design charts.

Introduction Carcinoma penis is more common in less developed areas of the world, such as parts of Africa, Asia, and South America where it accounts for 10-20% of malignancies inm men as against <1% in developed countries. Bihar being in developmental stage socioeconomically sees a very large proportion of patients suffering from penile cancers. We attempted to study the demographic characteristics of these patients. Methods A total of 50 patients presenting to our hospital between May2016 to April 2017 were included in this study and studied for various pre-determined demographic factors which included age, socioeconomic status, BMI, district of residence, grade and stage of disease and need for total or partial penectomy. All penile amputations except T1a(G1, 2) were combined with a bilateral inguinal nodal clearance. Results Average age of patients included in this study was 48.2 years (range 25-74 years). 80% of the patients belonged to low socio-economic class while majority of the patients hailed from Dharbhanga, Sharasa, Purnia, Chhapra and Khagaria districts which had 24%, 20%, 18%, 14% and 10% contribution respectively. 50% of the patients presented with Grade II disease. 14% had histopathology reported as Verrucous carcinoma. T2 N1 was the most common stage at presentation(40%). None of the patients in this study had systemic metastasis at presentation. Partial penectomy was needed in 70% while 30% had to undergo total penile amputation for want of adequate clear margins. [ABSTRACT FROM AUTHOR]

Background: Response to neoadjuvant chemotherapy (NACT) for breast cancer in patients with LABC is considered to be an important prognostic factor; but there are limited studies to evaluate preoperative response assessment in patients with locally advanced breast cancer (LABC) after NACT. We estimated the accuracy of ultrasound (US) to predict pathologic response after NACT using common response criteria and pCR definitions Methods: A total of 185 patients presenting with locally advanced breast cancer were subjected to pre-operative ultrasound of axilla after completion of NACT. Histo-pathologic assessment of Axillary Lymph Node dissection specimen was considered as gold standard and used to assess the sensitivity, specificity and accuracy of axillary ultrasound. Results On axillary ultrasound examination of 185 post NACT patients, 131 were found to have demonstrable LN in the axilla, of these, only 108 harboured metastasis. USG could successfully detect 108/121 histologically positive lymph nodes. USG showed 89.25% sensitivity and 63.49% specificity for overall nodal status. For N1 disease, USG could correctly classify 73/86 as N1. Its sensitivity was 84.88a%, which much higher than that of clinical examination only. The specificity for USG was 63.49%. The sensitivity and specificity of USG for N2 disease was 71.42% and 100% respectively, similar to that for clinical examination alone offering no added advantage in N2 disease. Conclusions: Pre-operative axillary ultrasound examination is a good tool for assessment of response and tailoring of further therapy after NACT. This accuracy increases for higher N stages. Combining this with guided FNAC may further improve the accuracy in assessing response. [ABSTRACT FROM AUTHOR]