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    <title>Transport Research International Documentation (TRID)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <title>Predicting Actual Temperature of an Autoclave for Composite Materials Using Balanced-ElasticNet</title>
      <link>https://trid.trb.org/View/2528570</link>
      <description><![CDATA[The production of high-performance rigid and lightweight composite materials is a top priority in automotive, defense, and aerospace industries. Therefore, it is crucial to introduce technologies related to Industry 4.0 to innovate the industrial production process. In the recent era, the use of an Artificial intelligence (AI) technology has exponentially grown and obtained significance as a powerful tool for simulating and modelling complex physical systems. Specifically, the autoclaving process facilitates the curing of composite materials of high-performance aerospace, automotive, and ships to get the desired strength and rigidness of the final product. The composite materials are subjected to high pressure and temperature to get durable, lightweight, and rigid products. Therefore, it is necessary to predict the actual temperature of an autoclave to obtain the desired strength and rigid products. In this work, the authors employed different machine learning (ML) approaches, namely, random forest, decision tree, gradient boosting, linear, multilayer perceptron, ridge, and balanced-ElasticNet regression for the prediction of the actual temperature of an autoclave. The elastic Net regression combines the penalties of both lasso and ridge regression and addresses the limitations of both. However, the authors introduced a balanced-ElasticNet by equaling both penalties to get the regularization and to handle the multicollinearity. The approach based on balanced-ElasticNet performs better compared to other ML approaches. Furthermore, the authors evaluated the performance using the historical data of 13 different batches and it obtained mean absolute error, root mean square error, R-2 squared error, and temperature relative error of 1.95, 5.71, 0.90, and 0.05, respectively. The authors also made a comparative analysis using different machine-learning approaches to check the reliability of approaches for accurate prediction of the actual temperature of an autoclave. However, the comparative analysis confirms the reliability of the balanced-ElasticNet-based approach for accurate prediction of an autoclave’s temperature. Furthermore, the proposed approach can assess, monitor, and improve the curing production processes of Dallara, which can lead to the production of the safest and most reliable lightweight and rigid products in the world.]]></description>
      <pubDate>Fri, 16 May 2025 09:33:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2528570</guid>
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    <item>
      <title>Improvement in geotechnical properties of soft filter cake stabilized with autoclaved aerated concrete powder: experimental evidence and micro-mechanism</title>
      <link>https://trid.trb.org/View/2186193</link>
      <description><![CDATA[Filter cake is a type of engineering waste soil composed of fine-grained particles, typically characterized by its high initial saturation and poor engineering performance. In this study, autoclaved aerated concrete powder (AACP) was used as an admixture to improve the mechanical properties of filter cake. The effects of AACP content and curing time on the unconfined compressive strength (UCS) and volume change behavior of compacted specimens were investigated. The test results showed that the UCS of compacted AACP/filter cake mixtures initially increased with increasing AACP content, reaching a peak value at 40% AACP content, and subsequently decreased. The sample containing 40% AACP (cured for 28 days) exhibited a constrained modulus comparable to that of conventional embankment filling materials, but with the added advantage of a lower dry density. Expansion of the parent soil, when exposed to water, occurred through interparticle expansion. The addition of AACP resulted in a reduction in the thickness of the diffuse double layer (DDL) of clay particles, as well as a decrease in the interparticle repulsive force. This allowed soil particles to approach each other more closely and facilitated the formation of aggregated soil particles. AACP incorporation further altered the particle size distribution and soil structure, thereby contributing to the improvement in mechanical properties of the filter cake. The physicochemical and microstructural observations, such as SEM, XRD, and MIP analyses, and zeta potential tests, were in good agreement with the changes in the geotechnical properties of the samples. These experimental results provide technical references for the utilization of AACP and filter cake in embankment engineering.]]></description>
      <pubDate>Wed, 28 Jun 2023 16:29:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2186193</guid>
    </item>
    <item>
      <title>Performance of Thermally Activated Sugarcane Bagasse Ash as Supplementary Cementitious Material</title>
      <link>https://trid.trb.org/View/1468129</link>
      <description><![CDATA[Both in the production of clinker and as a supplementary cementing material in ordinary Portland cement (OPC) in order to improve specific properties of concerete, the use of pozzolanic material has increased. The burning of bagasses in boilers in the sugarcane industry produces sugarcane bagasse ash (SCBA) as a residue. The effect of inclusion of SCBA on hydration temperature, autoclave expansion, and compressive and flexural tensile strength of bagasse ash mortar and concrete is investigated in this experimental research program. Bagasse ash replaced cement in different proportion ranging 10-25 percent in 5 percent increments. While autoclave expansion and hydration temperature were reduced, the use of bagasse ash improves compressive and tensile flexural strengths, as indicated by the experimental test results.]]></description>
      <pubDate>Thu, 25 May 2017 13:56:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/1468129</guid>
    </item>
    <item>
      <title>Influence of Fluidized Ashes on Properties of Autoclaved Aerated Concrete</title>
      <link>https://trid.trb.org/View/1420739</link>
      <description><![CDATA[Coal fly ash, a by-product of coal combustion in thermal power plants, is one of the most complex and abundant anthropogenic materials. For several years, siliceous fly ash has been predominantly used as a substitute for material in the construction industry, either as a raw material or as an additive in the cement industry all over the world. Fly ash produced in coal-fired plants based on fluidized bed combustion technology accompanied by in-furnace desulfurization has significantly different properties compared to siliceous ashes. In this study, a brief characterization of fly ash from fluidized bed boilers is presented and possible alterations in fly ash use in autoclaved concrete production are discussed. Autoclaved aerated concrete production involving fluidized ashes proved to be more cost-effective and environmentally friendly. The content of lime and sulfates was found to be reduced by 10% to 20% and 60% to 100%, respectively, which limited the exploitation and consumption of the natural raw materials.]]></description>
      <pubDate>Mon, 29 Aug 2016 11:08:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/1420739</guid>
    </item>
    <item>
      <title>STUDIES ON HYDRATION QUANTITATIVE ANALYSIS AND SULFATE RESISTANCE OF Ca-Mg-Si-BASED CEMENT MATERIALS WITH AUTOCLAVE CURING</title>
      <link>https://trid.trb.org/View/1351795</link>
      <description><![CDATA[The purpose of this research is to evaluate the effect of using Ca-Mg-Si-based materials and autoclave curing to the sulfate resistance, and clarify the mechanism of sulfate resistance from the view point of the hydration quantitative analysis, FT-IR and ²⁹Si NMR. As a result, the sulfate resistance was improved by the Ca-Mg-Si-based materials substitution with autoclave curing. In addition, the generation of Mg-tobermorite could possibly contribute to the sulfate resistance in the case of raw Ca-Mg-Si-based materials substitution ratios, while C-M-S-H with low C/S ratio and high-polymerized silicate chains could possibly contribute to the sulfate resistance in the case of high Ca-Mg-Si-based materials substitution ratios.本研究ではCa-Mg-Si系材料をケイ石微粉末と共にセメントに置換し、オートクレーブ（AC）養生を実施した試料について水和反応解析を行い、トバモライトをはじめとしたAC養生後の水和生成物と硫酸塩抵抗性とを関連づけて考察することを目的とした。その結果、オケルマナイトはAC養生下で反応性を示し、Mg型トバモライトやケイ酸カルシウムマグネシウム水和物などの生成に寄与したことがわかった。またXRDによる水和反応解析、FT-IRおよび²⁹Si NMRの結果を総合すると、オケルマナイト置換およびAC養生による耐硫酸塩性向上の要因は、低置換率においてはMg型を含むトバモライトが多量に生成したことにより、高置換率においてはトバモライト構造を維持しつつ、重合度が高いシリケート鎖を有した低C/S比のケイ酸カルシウムマグネシウム水和物等が生成したことによるものと考察した。]]></description>
      <pubDate>Tue, 26 May 2015 16:12:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/1351795</guid>
    </item>
    <item>
      <title>STUDIES ON THE SULFATE RESISTANCE OF CEMENT-BASED MATERIAL MIXED THE Ca-Mg-Si-BASED MATERIALS AND WATER CURING AND AUTOCLAVE CURING</title>
      <link>https://trid.trb.org/View/1351613</link>
      <description><![CDATA[Nowadays, in the Middle East region where sulfate is abundantly found in soil, the sulfate attack on concrete structures is one of the serious problems. On the other hand, in japan, the utilization of industrial-by-product for cementitious material is required from the viewpoint of environmental protection and forming recycling society. Ca-Mg-Si based materials can be generated from industrial-by-products such as Steelmaking slag. However, Ca-Mg-Si based materials are not being used yet. Consequently, the using of Ca-Mg-Si based materials is contributes to the reduction of the environmental burdens and economical load. Therefore, the purpose of this study was to establish the material design of the high durability of cementitious material using Ca-Mg-Si based materials. In this study, the sulfate resistance of the hardened bodies formed by autoclave curing or underwater curing, using cement, silica powder, and Ca-Mg-Si based materials, such as Akermanite and Merwinite, was examined. Then, porosity, length change ratio from sulfate immersion test was measured. And identification of product materials inside hardened body based on x-ray diffraction (XRD) was done.As the experimental results, in the cases of 40％ Ca-Mg-Si based materials substitution ratio with underwater curing, the length change ratios had the values that lower than 0.1％. Furthermore, in the cases of specimens formed by Ca-Mg-Si based materials with autoclave curing, the length change ratios were quite lower values that less than 0.07％. This is due to the generation of tobermorite at low substitution ratio and Si structure like tobermorite at high substitution ratio.本研究では、普通ポルトランドセメント（OPC）とケイ石微粉末および、製鋼スラグ等の産業副産物に含有するCa-Mg-Si系材料を用い、水中養生およびオートクレーブ（AC）養生を行った供試体の硫酸塩抵抗性を、反応生成物や結晶構造と関連付けて考察し、耐硫酸塩性に優れた高耐久コンクリートの材料設計の提案を目的とし検討を行った。その結果、水中養生では、OPCをCa-Mg-Si系材料により40％置換することで硫酸塩抵抗性の向上が認められた。AC養生では、Ca-Mg-Si系材料の混和のみによって更に硫酸塩抵抗性が向上した。これは、Ca-Mg-Si系材料の混和とAC養生によって供試体中に化学的安定性を有するトバモライトや、トバモライトと同様のSi構造を有する化合物が生成したためと考察した。]]></description>
      <pubDate>Thu, 30 Apr 2015 09:24:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/1351613</guid>
    </item>
    <item>
      <title>Study on Fully and Highly Efficiently Recycling of Waste Concrete</title>
      <link>https://trid.trb.org/View/1114475</link>
      <description><![CDATA[The disposal of waste concrete has been a serious problem. In this paper, a new method of fully and highly efficiently recycling of waste concrete is proposed. The method is as follows: first the components of waste concrete are separated by crushing, heating, grinding, and powder selecting with wind power, then, the separated component of the hardened cement paste powder is calcined to prepare regenerated binding material, and the separated components of ground and calcined mortar are used to prepare high strength lime-silica material. Experiments were carried out to verify the validity of the proposed method. Experimental results indicate that highly reactive regenerated binding material containing the phase of cryptocrystalline beta-C2S, can be prepared by burning the separated hardened cement paste powder at 650 degrees C. And lime-silica material with the compressive strength of 97.2 MPa can be prepared by the mortar powder separated from waste concrete in the autoclaving curing.]]></description>
      <pubDate>Mon, 29 Aug 2011 14:56:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1114475</guid>
    </item>
    <item>
      <title>Autoclaves for Aerospace Applications: Issues and Challenges</title>
      <link>https://trid.trb.org/View/1105397</link>
      <description><![CDATA[The Council of Scientific and Industrial Research National Aerospace Laboratories (CSIR-NAL), Bangalore, India has been engaged in the research of autoclaves for the past three decades and has pioneered their development and usage in India for aerospace/aircraft structural applications. The autoclaves at CSIR-NAL have played a significant role in all the major national aircraft/aerospace programs. Autoclaves are now being used to produce very large aircraft components such as wing and fuselage. The largest aerospace autoclave in India (working size of 4.4 m diameter and 9.0 m length) has been successfully commissioned at CSIR-NAL. This paper gives the technological challenges faced and the innovative concepts that were introduced in these autoclaves.]]></description>
      <pubDate>Wed, 20 Jul 2011 07:24:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/1105397</guid>
    </item>
    <item>
      <title>Production of monetite-based Inorganic Phosphate Cement (M-IPC) using hydrothermal post curing (HTPC)</title>
      <link>https://trid.trb.org/View/1084384</link>
      <description><![CDATA[A new hydrothermal post curing (HTPC) technique is developed in this study to overcome the long term evolutions such as shrinkage and cracking of Inorganic Phosphate Cement (IPC). HTPC is based on thermally induced transformation of the unstable calcium phosphates phases, e.g. brushite and amorphous calcium phosphate (ACP), into more stable phases, e.g. monetite, with prevention or minimization of the bulk shrinkage during the treatment. To achieve this effect, sufficient pore moisture is kept in IPC during the transformation stage. This way, the increase of skeletal density thus does not necessarily lead to significant global bulk shrinkage, since the contraction of the skeleton is replaced internally by an increase of the pore size. This effect can be obtained by post curing in the autoclave, when a sufficiently high temperature is used to provoke the necessary structural transformation, combined with a pressure high enough to force the pore moisture and the released bound water to stay inside the pores. After evaluation of this technique, it was noticed that the monetite percentage in the hydrothermally post cured IPC products increases from 26% to 39%, compared to the heated reference IPC. It is also verified that additional pore volume replaced the bulk shrinkage that would occur when IPC is heated without autoclave pressure. This new modified IPC end product is called monetite-based IPC (M-IPC).]]></description>
      <pubDate>Wed, 19 Jan 2011 10:52:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/1084384</guid>
    </item>
    <item>
      <title>Porosity and Mechanical Strength of an Autoclaved Clayey Cellular Concrete</title>
      <link>https://trid.trb.org/View/980865</link>
      <description><![CDATA[This paper investigates the porosity and the mechanical strength of an Autoclaved Clayey Cellular Concrete (ACCC) with the binder produced with 75 wt% kaolinite clay and 25 wt% Portland cement. Aluminum powder was used as foaming agent, from 0.2 wt% to 0.8 wt%, producing specimens with different porosities. The results show that the specimens with higher content of aluminum presented pore coalescence, which can explain the lower porosity of these samples. The porosities obtained with the aluminum contents used in the study were high (approximately 80%), what accounts for the low mechanical strength of the investigated cellular concretes (maximum of 0.62 MPa). Nevertheless, comparing the results obtained in this study to the ones for low temperature clayey aerated concrete with similar compositions, it can be observed that autoclaving is effective for increasing the material mechanical strength.]]></description>
      <pubDate>Wed, 27 Oct 2010 07:15:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/980865</guid>
    </item>
    <item>
      <title>Effect of Aggregate Type on Mechanical Properties of Reactive Powder Concrete</title>
      <link>https://trid.trb.org/View/968901</link>
      <description><![CDATA[This aricle focuses on the experimental study of the mechanical properties of reactive powder concrete (RPC) that is produced with different aggregates, such as korund, basalt, limestone, quartz, sintered bauxite, and granite. The effects of aggregate type on mechanical properties were investigated under standard, atmospheric, and high-pressure steam curing in this article. The test results indicate that very high compressive strength can be achieved even with low-strength or smooth-surface aggregates; however, superior flexural performance requires high-strength aggregate with rough surface characteristics. A compressive strength of approximately 200 MPa (29 ksi) can be obtained when strong and rough-surface textured aggregate were used under standard curing conditions. Atmospheric and high-pressure steam curing improved the compressive strength significantly. These curing regimes, however, did not considerably improve the flexural performance. Pressure application in fresh state resulted in a great improvement of the compressive strength of RPC, particularly in the case of high-strength and rough-surface textured aggregates. In this way, a compressive strength over 400 MPa (58 ksi) was obtained with bauxite aggregate after pressure application and autoclaving.]]></description>
      <pubDate>Thu, 21 Oct 2010 08:02:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/968901</guid>
    </item>
    <item>
      <title>Cement Soundness and the Autoclave Expansion Test - An Update of the Literature</title>
      <link>https://trid.trb.org/View/875474</link>
      <description><![CDATA[The autoclave expansion test (ASTM C 151) is used to provide an index of potential delayed expansion caused by the hydration of CaO and MgO in hydraulic cements. Questions have arisen over the years regarding the effect of excess crystalline free MgO (periclase) on cement soundness and concrete durability under actual service conditions. It has been suggested that the autoclave expansion test is overly severe and will exclude cements that perform well in concrete under field service conditions with no reduction in long-term durability. Other experimental protocols and tests for soundness have also been developed and investigated over past years, including an update of the Le Chatelier Soundness Test and a number of other modifications in testing temperatures and time of testing. Chemical compositional influences on periclase formation and the resistance of cement or concrete to expansion have also been identified. The purpose of this literature review is to update and supplement previous reviews on this topic.]]></description>
      <pubDate>Tue, 30 Dec 2008 12:37:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/875474</guid>
    </item>
    <item>
      <title>Ninth CANMET/ACI International Conference on Fly Ash, Silica Fume, Slag and Natural Pozzolans in Concrete</title>
      <link>https://trid.trb.org/View/813207</link>
      <description><![CDATA[The Ninth CANMET/ACI International Conference on the Use of Fly Ash, Silica, Fume, Slag and Natural Possolans was held May 20-25, 2007 in Warsaw, Poland. More than one hundred papers were presented at the general sessions. This publication will present thirty-nine papers from the sessions. The main purpose of the conference was to bring together representatives from industry, universities, and government agencies to present the latest information on then materials of discussion and to discuss areas that require research.]]></description>
      <pubDate>Fri, 20 Jul 2007 09:55:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/813207</guid>
    </item>
    <item>
      <title>Sulfate Resistance of Mortars Made from Cements Containing Fluidized-Bed Coal Combustion Wastes</title>
      <link>https://trid.trb.org/View/813391</link>
      <description><![CDATA[The purpose of the research program was to investigate how the addition of new-generation wastes produced in the coal-fired power plant, fluidized-bed type installations, impact mechanical properties and chemical durability of cements.  Tests were made on cements that were derived from two portland cement clinkers containing wildly different amounts of C3A. With the addition of the fluidized-bed material from the brown and black coal combustion systems blended portland cements were made.  The properties of these blended cements were compared with those of the reference portland cements.  The composition of all cements was adjusted in order to achieve the maximum permissible amount of SO3, i.e. 35%.  Three different curing procedures were used for mortar specimens:  normal temperature and humidity conditions, low pressure steam curing, and autoclaving.  Durability to sulfate attack was studied using two methods: one method involved the monitoring of linear dimensions of 20x20 x 160 mm mortar prisms cured under different conditions and exposed to aqueous solutions of Na2SO4 and MgSO4, with 16+/- 0.5 g/l concentration of SO4(2) anions.  The other method involved investigation of changes of mechanical properties of 25x25x100 mm mortar prisms cured under different conditions and subjected to prolonged sulfate exposure.  The strength of samples was measured after different times of exposure in sulfate.]]></description>
      <pubDate>Fri, 20 Jul 2007 09:55:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/813391</guid>
    </item>
    <item>
      <title>Autoclaved SIFCON with high volume Class C fly ash binder phase</title>
      <link>https://trid.trb.org/View/781547</link>
      <description><![CDATA[This paper examines the effect of incorporating high volume, Class C fly ash (FA) on mechanical properties of autoclaved SIFCON (slurry infiltrated fiber concrete). Cement was replaced with up to 60% FA in SIFCON compositions and 3 different steel fiber volumes (2%, 6%, and 10%) were used. Test results are presented in comparison with the control mix (0% FA and 0% fiber). Mechanical properties were positively affected at almost every FA replacement. Moreover, by increasing the fiber volume, flexural strength and toughness were remarkably increased. This behavior was more pronounced at 10% fiber volume. At this fiber volume ratio, flexural strength of 55 MPa could be achieved with 60% FA replacement.]]></description>
      <pubDate>Wed, 31 May 2006 09:29:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/781547</guid>
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