Innovations in concrete pavements for a sustainable infrastructure

Concrete pavements (CPs) are durable and they do not need periodic invasive maintenance interventions. Nevertheless, CPs are hardly chosen when only initial costs, instead of life-cycle costs, are considered in the evaluation. Nowadays, there are innovations in Jointed Plain Concrete Pavements (JPCPs) that reduce initial costs about 25% with respect to alternatives with equivalent structural capacity. This paper addresses the question if the innovations early-entry saw-cutting of joints, joints without seals and shorter joint spacing (without dowels bars) are able to maintain the traditional life-cycle performance of CPs. All these innovations affect the joints of the JPCP, and these ones the JPCP performance. Accordingly, the objective of the present paper is to analyse the effects of the joints behaviour on the performance of the JPCPs innovations. The joint behaviour is characterized by the joint activation and opening, the joint capacity to transfer traffic loads and the joint deterioration. The calculations of the joints activation and opening are made with a model developed by the authors. For the estimation of the joint transfer capacity; the results of finite-element software are used. The analysis is completed with field data of the JPCPs innovations. The innovations analysed contribute to a sustainable infrastructure as they can maintain, and even improve, the traditional life-cycle performance of CPs with lower initial costs. Nevertheless, for the design hypotheses to be valid, it is necessary to assure the joints activation and to limit the joints opening to 1.2 mm. With this purpose, for the analysed conditions, it is recommended to cut the joints at least at 30% of the JPCP thickness.Structural EngineeringCivil Engineering and Geoscience

Rpas based tracking of machinery used in asphalt paving process

Application of rigorous construction procedures is fundamental when it comes to road construction. Nowadays, and in particular in Chile, the asphalt paving construction process is based on tradition, craftsmanship and other implicit, experience-based methods employed during road construction. This means, that the different stages of the construction process, including the paving of the road, are not controlled on time as they should, which causes that the final product does not have the ideal characteristics for which the construction materials initially were designed and manufactured. Therefore, we propose the use of tools and methodologies that allow monitoring each of the stages of the construction process in almost real-time. Our approach aims to evaluate the use of Remotely Piloted Aircraft Systems (RPAS) during the asphalt pavement construction process by capturing images and videos during the placement of the asphalt mixture and the movement of the compaction machinery (pneumatic roller and drum roller) present in the construction site. The observations are digitally processed by mainly binarization and thresholding. As a result, the macro texture of the asphalt surface was estimated and the trajectory of the compaction rollers was visualized. In conclusion, our results reveal that the main factor that influences the quality of the roads corresponds to the performance and operations of the compaction machinery

Role of transcription factors in the beneficial effect of 3-day high CO2 pretreatment during postharvest storage at low temperature of table grapes

Trabajo presentado al 8th International Table Grape Symposium, celebrado en Apulia & Sicily (Italia) del 1 al 7 de octubre de 2017.[Background and Aims]: Table grape (Vitis vinifera L.) is a non-climacteric fruit, tolerant to low temperature. However, their quality deteriorates during postharvest storage at low temperature mainly because of sensitivity to fungal decay and senescence of rachis. The application of a 3-day CO2 pretreatment (20% CO2 + 20% O2 + 60% N2) at 0ºC reduced total decay and retained bunches quality during postharvest storage. However, the molecular mechanisms involved in this process are not well known. In a recent work, we have shown that the maintenance of Cardinal table grape quality by the 3-day gaseous pretreatment seems to be an active process, activating transcription factors such as WRKYs and ERFs (Ethylene Responsive Factors). In addition, we have observed that the gaseous pretreatment modulated the expression of VviDREBA1-1 in the pulp and rachis of table grapes cv. Cardinal. The fact that DREBA1-1 belong to the same transcription factor family that ERFs seems to indicate that this family could play an important role in the beneficial effect of the gaseous treatment to maintain table grape quality. To better understand the role of transcription factors in the maintenance of table grape quality at low temperature by the application of high CO2 levels we have characterize 5 VviERFs, 3 VviDREBA1s and 15 VviWRKYs in two table grapes cultivars, such as Cardinal and Autumn Royal. Furthermore, to study the role of ERFs/WRKYs in the regulation of pathogenesis related proteins (PRs), and DREBA1s in the regulation of dehydrins (DHNs) in table grapes, we have analyzed the pattern of expression of three PRs (thaumatin (VviTL1), chitinase (Vcchit1b) and β-1,3-glucanase (Vcgns1)) and three DHNs (VviDHN1a, VviDHN2 and VviDHN4) in different tissues of bunches CO2-treated and non-treated. Furthermore, we have identified different cis-regulatory elements, including the GCC/W-box and DRE/CRT motifs, respectively and we have examined the DNA-binding specificities of the mentioned transcription factors by using electro mobility shift (EMSA) assays.[Experimental Procedure and Main Results]: Table grapes (Vitis vinifera L.) cv. Cardinal were harvested in Camas, Seville, Spain in July 2003 at the early commercial stage (maturity index: 15.24) and table grapes cv. Autumn Royal were picked in Abarán, Murcia, Spain in November 2013 at the late commercial stage (maturity index: 27.97). After random harvesting, bunches were transported in the same day to the laboratory in Madrid (Spain) and treated according to. For each sample, total RNA was extracted three times according to, and treated with DNase I recombinant-RNase free (Roche) for genomic DNA removal. Then, 1 μg of each extraction was used to synthesize cDNA as described by. Relative expression of VviERFs, VviDREBA1s and VviWRKYs, as well as spliced and unspliced transcripts of VviDHN4 was assayed using quantitative RT-PCR (RT-qPCR) as described by. Spliced and unspliced variants of VviDHN1a and VviDHN2 were evaluated by semi-quantitative RT-PCR as described by. The full VviERFs, VviDREBA1s and VviWRKYs open reading frames, including stop codons were amplified by RT-PCR, cloned as N-terminal fusion with an amino acid His tag in pTrcHisA vector (Invitrogen, Carlstad, USA) and transformed into BL21-CodonPlus (DE3)-RIL competent cells as described by. The induction and purification of recombinant proteins was performed according to. Purified recombinant proteins were used to determine DNA binding by EMSA assay. The GCC box, DRE/CRT motifs and W-box were used as probes. Binding reactions were performed in 20 μl final volume containing 2 μg of recombinant proteins, 50 μM unlabeled DNA, 80 nM Biotin-labeled probe, 50 ng μl-1 Poly (dI·dC), 2.5% (v/v) glycerol and 1X binding buffer.[Main results]: Our results showed that in most of the Cardinal tissues analyzed the VviERFs gene expression was induced after storage under normal atmosphere, although applying high levels of CO2 at 0ºC caused a greater increase in VviERFs transcript accumulation. However, the pattern of expression was different depending on both the tissue and VviERFs. In table grapes cv. Autumn Royal, the 3-day high CO2 treatment applied at 0ºC modulated the expression of VviDREBA1s by activating VviDREBA1-1 and VviDREBA1-7 in the skin, and VviDREBA1-6 and VviDREBA1-7 in the pulp. On the other hand, it is important to note that the effect of low temperature storage under normal atmosphere modulated VviDREBA1-1 and VviDREBA1-7 after 13 days of storage, while the three VviDREBA1s were induced at the end of the 3-day gaseous treatment at 0ºC. This temporal difference could be important to help table grapes face temperature shifts at 0ºC. The gaseous treatment also activated the expression of WRKYs transcription factors in a tissue-dependent manner in Autumn Royal bunches, inducing levels of 4 VviWRKYs in the skin and 9 in the pulp. The promoter regions of Vcchit1b and Vcgns1 had in common the presence of a single W-box and a GCC box. However, the VviTL1 promoter region included a W-box but not a GCC-box. By other hand, the study of the VviDHNs promoter regions showed that, whereas the VviDHN1 promoter presented a DRE element and the VviDHN2 promoter one DRE element and one CRT element, VviDHN4 did not show any of them. The EMSA assays provided evidences that recombinant VviERF2 and VviERF11 bound specifically to the GCC box presented in the promoter of the above mentioned PRs. However, VviERF069 and VviERF10 can only bind to the GCC box of the Vcgns1 promoter and VviERF6L7 showed no affinity for any of the GCC box studied. However, while VviWRKY14 presented affinity for the W-box of the three PR promoters, VviWRKY42 only had specific affinity to the W-box of the Vcgns1 promoter. In addition, it was showed that VviDREBA1-1 is the only transcription factor analyzed from this family that was able to bind in vitro to the CRT element (GCCGAC) presented in the VviDHN2 promoter.[Significance of the Study and Conclusions]: To date, there has been no comprehensive analysis regarding the transcriptional responses of transcription factors genes to postharvest storage conditions associated with mechanisms underlying abiotic stress responses, such as low temperature or modified atmosphere. Our work, suggested that the beneficial effect of high CO2 treatment maintaining table grape quality of different cultivars during storage at low temperature seems to be mediated by the regulation of ERFs, DREBA1s and WRKYs transcription factors. In particular, it is interesting to note that VviERF2 gene expression an induction by high CO2 levels in all the tissues analyzed and a significant correlation with the expression of the Vcchit1b and Vcgns1, together with the in vitro binding affinity observed with the GCC box of their promoters. By other hand, the fact that VviDREBA1-1 was the only transcription factor analyzed that presented in vitro binding capacity to the CRT element of the VviDHN2 promoter region, indicated that the transcriptional regulation of VviDHN1a and VviDHN4 would be carried out by activating other independent routes of these transcription factors. These results open interesting.This work was supported by the European Union under the 7th Framework Programme FP7-PEOPLE-2012-CIG no. 321694 and by CICYT projects AGL2011-26742 and AGL2014-53081-R. M.V-H was supported by a predoctoral contract from the MEC.Peer Reviewe

WRKY transcription factors in the response of table grapes (cv. Autumn Royal) to high CO2 levels and low temperature

WRKY transcription factors are regulated by biotic and abiotic stress in Vitis vinifera, although little is known about their role in grape berries. The latest V. vinifera reference genome (PN40024 12 × .v2, VCOST.v3 annotation) gave us a good opportunity to perform an analysis of VviWRKYs, identifying 61 genes. Our study examines whether the application of high CO2 levels for 3 d to maintain table grape quality activated the gene expression of 15 WRKYs in the skin and pulp of grapes (cv. Autumn Royal) stored at 0 °C. Results showed that the induction of VviWRKYs gene expression by CO2 was tissue dependent, being this effect mainly observed in the pulp where 9 out of the 15 genes analyzed were activated by the gaseous treatment. The expression analysis of genes associated with ethylene (ACC synthase1 (ACS1) and ACC oxidase1 (ACO1)) and ABA (9-cis-epoxycarotenoid dioxygenase1 (NCED1)) biosynthesis indicated that the expression of ACO1 in the skin of non-treated samples and in the pulp of CO2-treated ones correlated with the changes observed in VviWRKYs. In addition, we studied the role of WRKYs in the modulation of genes encoding pathogenesis-related proteins (PRs) in table grapes. Results showed there was a significant positive correlation between WRKYs modulated by CO2 in the skin and pulp with a β-1,3-glucanase (Vcgns1) and a thaumatin (VvTL1), respectively. Through electrophoretic mobility shift assay (EMSA) we observed that VviWRKYIIa_3 recombinant protein was able to in vitro bind to the W-box present in the promoter of the three PRs analyzed while VviWRKYIII_3 was only able to specifically bind to the Vcgns1 probe. Our results support the fact that high CO2 treatment is an active process that requires the activation of transcription factors, such as those of the WRKY family, which could participate in the molecular events involved in maintaining table grape quality during postharvest.This work was supported by CICYT projects AGL2014-53081-R and AGL2017-85291-R (MINECO/AEI/FEDER, UE). MV-H was supported by a predoctoral contract from the MEC.Peer reviewe

The realities of additively manufactured concrete structures in practice

Extrusion-based 3D Concrete Printing (3DCP) is rapidly gaining popularity in the construction industry. Trial projects are now being realized at an increasing rate around the world to test the viability of the technology against real-world requirements. This step, from the ‘simple’ deposition of filaments of self-stable concrete to its application in buildings and structures, with all associated requirements and interfaces, comes with challenges. These range from matching the design intent to the manufacturing capabilities (through structural analysis and approval, and reinforcement) to quality consistency (robustness) on large scale, and compatibility with other materials. In many of these areas, much simply remains unknown due to a lack of experimental data or information from projects where 3DCP has been applied. This paper aims at reducing this knowledge gap by presenting a systematic discussion, based on the analyses of eight realized 3DCP projects from around the world. It was found that the structural application of printed concrete is limited, due to a lack of regulatory framework for expedient approval, as well as limited reinforcement options which require to resort to unreinforced masonry analogies. The application of the technology features a host of practical issues that relate to the print process, material, site conditions, building integration and design – or to the 3DCP technology in general. Although some potential risks, such as shrinkage cracking and quality consistency are generally recognized, the measures taken to mitigate them vary considerably, and are largely based on individual expertise. The actual effectiveness is generally unknown. Finally, it was observed that, while the printing itself is fast, the preparation time is generally considerable. This is partially due to a lack of knowledge amongst professionals. In the practical production of a 3DCP project, three expertise areas are crucial: one for the digital part, one for the machine side, and one for the material side. Thus there is a strong need for educational institutions to develop dedicated training courses and incorporate relevant topics into their curricula