Effect of using 3D-printed shell structure for reinforcement of ultra-high-performance concrete

This study aims to investigate the effect of 3D-printed polymer shell reinforcemen ton ultra-high-performance concrete. The mechanical properties of ultra-high-performance polymer reinforced concrete have been investigated. At first, the 3D-printed shell reinforcements were designed using 3D Max and Rhino 6 software. Then, each was fabricated through the fused deposition modeling method and positioned into the cubic, cylindrical, and prismatic molds. In the next step, the prepared Ultra-High-Performance Concrete mixture was poured into the molds, and the samples were cured for 28 days. Finally, the compressive, tensile, and flexural strength tests were carried out on the samples. The results indicated that the compressive, tensile, and flexural strengths of reinforced samples were lower than that of the unreinforced ones, respectively. Although including 3D-printed reinforcement decreased the mechanical properties of the Ultra-High-Performance Concrete samples, it changed the fracture mechanism of concrete from brittle to ductile

Effect of gelatin powder, almond shell, and recycled aggregates on chemical and mechanical properties of conventional concrete

The objective of the research is to study the effect of different additives on the conventional concrete. In this term, three types of materials have been added to the concrete: gelatin powder as the binder, recycled aggregates, and almond shell as the fine and coarse aggregates. Several experiments have been made tо determine physical and mechanical properties, such as test for compressive and tensile strengths, for impact loading strength, durability test (water absorption) and deep penetration tests. Moreover, the microstructure results for the new type of concrete have been studied by means of scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDXS). The results show that when 70 kg of gelatin powder is added to 1 m3 of concrete, the concrete’s compressive strength and tensile strength are improved more than 22%; during impact loading the first and ultimate cracks are 11 and 129 by numbers, and the first and ultimate cracks’ strength is more than 223 and 2346 J respectively. The durability of sample from concrete with additional gelatin has been improved. SEM results illustrate that the weakness of almond shell concrete is related to cracks and voids between the cement matrix and almond shell. The voids of gelatin concrete are higher than that of conventional concrete. The conventional concrete has smooth crystals, and gelatin concrete has sharp and cubic crystals. EDXS results show that chemical content of these two types of concrete is different: conventional concrete contains silicon, while EDXS results show that chemical content of these two types of concrete is different: conventional concrete contains silicon, while gelatin concrete contains calcium and also C-S-H gel is generated in it

Historical structure design method through data analysis and soft programming

AbstractThe present study is focused on the method of designing historical structures through data analysis and soft programming. The current research aimed to find the design method of the old columns of the structure and compare it with modern design methods. The case study was Goharshad Mosque (1400 AC) located in Iran, Mashhad. A correlation matrix was created to find the relationship between structure parameters by data mining in Python. The results indicate that the modern design method was more reliable than the old method due to the safety factor, but some parameters such as loading calculation in the historical method and the modern method were the same with more than 70% similarity. But the results of the coefficient of determination show that the loading of the R2 results was more than 0.44 and the area of the columns was more than −0.5. The modern and old design has a big engineering gap. Finally, the current study shows the old structure design method and compares it with the new design method

Influence of 3D-printed reinforcement on the mechanical and fracture characteristics of ultra high performance concrete

The current research makes an attempt to examine the possibility of using the 3D printing technique for the reinforcement of Ultra High-Performance Concrete (UHPC). In this regard, the mechanical properties and fracture mechanism of UHPC containing 3D-printed shell reinforcements made from Polylactic Acid (PLA) materials have been investigated. At first, the 3D-printed shell reinforcements were plotted with the aid of 3D Max and Rhino 6 software. Then, they were fabricated through Fused Deposition Modeling (FDM) method and positioned into the cubic, cylindrical and prismatic molds. At the next step, the prepared UHPC mixture was poured into the molds and the samples were cured for 28 days. Finally, the compressive, tensile and flexural strength tests were carried out on the samples. The results indicated that the compressive, tensile, and flexural strengths of reinforced samples were less than the unreinforced ones, respectively. Although the inclusion of 3D-printed reinforcement decreased the mechanical properties of the UHPC samples, it was able to change the fracture mechanism of concrete from brittle to ductile

Prediction of the Mechanical Properties of Basalt Fiber Reinforced High-Performance Concrete Using Machine Learning Techniques

In this research, we present an efficient implementation of machine learning (ML) models that forecast the mechanical properties of basalt fiber-reinforced high-performance concrete (BFHPC). The objective of the present study was to predict compressive, flexural, and tensile strengths of BFHPC through ML techniques and propose some correlations between these properties. Moreover, the modulus of elasticity (ME) values and compressive stress–strain curves were simulated using ML techniques. In this regard, three predictive algorithms, including linear regression (LR), support vector regression (SVR), and polynomial regression (PR), were considered. LR, SVR, and PR were utilized to forecast the compressive, flexural, and tensile strengths of BFHPC, and the PR technique was employed to simulate the compressive stress–strain curves. The performance of the models was also determined by the coefficient of determination (R2), mean absolute errors (MAE), and root mean square errors (RMSE). According to the obtained values of R2, MAE, and RMSE, the performance of PR was better than other types of algorithms in estimating the compressive, tensile, and flexural strengths. For example, R2 values were 0.99, 0.94, and 0.98 in predicting the compressive, flexural, and tensile strengths using PR, respectively. This shows the higher accuracy and reliability of the PR technique compared with other predictive algorithms. Finally, we concluded that ML techniques can be appropriately applied to assess the mechanical characteristics of BFHPC

The Prediction of Compressive Strength and Compressive Stress–Strain of Basalt Fiber Reinforced High-Performance Concrete Using Classical Programming and Logistic Map Algorithm

In this research, the authors have developed an algorithm for predicting the compressive strength and compressive stress–strain curve of Basalt Fiber High-Performance Concrete (BFHPC), which is enhanced by a classical programming algorithm and Logistic Map. For this purpose, different percentages of basalt fiber from 0.6 to 1.8 are mixed with High-Performance Concrete with high-volume contact of cement, fine and coarse aggregate. Compressive strengths and compressive stress–strain curves are applied after 7-, 14-, and 28-day curing periods. To find the compressive strength and predict the compressive stress–strain curve, the Logistic Map algorithm was prepared through classical programming. The results of this study prove that the logistic map is able to predict the compressive strength and compressive stress–strain of BFHPC with high accuracy. In addition, various types of methods, such as Coefficient of Determination (R2), are applied to ensure the accuracy of the algorithm. For this purpose, the value of R2 was equal to 0.96, which showed that the algorithm is reliable for predicting compressive strength. Finally, it was concluded that The Logistic Map algorithm developed through classical programming could be used as an easy and reliable method to predict the compressive strength and compressive stress–strain of BFHPC

Влияние порошка желатина, миндальной скорлупы и вторичных заполнителей на химические и механические свойства обычного бетона

The objective of the research is to study the effect of different additives on the conventional concrete. In this term, three types of materials have been added to the concrete: gelatin powder as the binder, recycled aggregates, and almond shell as the fine and coarse aggregates. Several experiments have been made tо determine physical and mechanical properties, such as test for compressive and tensile strengths, for impact loading strength, durability test (water absorption) and deep penetration tests. Moreover, the microstructure results for the new type of concrete have been studied by means of scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDXS). The results show that when 70 kg of gelatin powder is added to 1 m3 of concrete, the concrete’s compressive strength and tensile strength are improved more than 22%; during impact loading the first and ultimate cracks are 11 and 129 by numbers, and the first and ultimate cracks’ strength is more than 223 and 2346 J respectively. The durability of sample from concrete with additional gelatin has been improved. SEM results illustrate that the weakness of almond shell concrete is related to cracks and voids between the cement matrix and almond shell. The voids of gelatin concrete are higher than that of conventional concrete. The conventional concrete has smooth crystals, and gelatin concrete has sharp and cubic crystals. EDXS results show that chemical content of these two types of concrete is different: conventional concrete contains silicon, while EDXS results show that chemical content of these two types of concrete is different: conventional concrete contains silicon, while gelatin concrete contains calcium and also C-S-H gel is generated in it.Цель исследования - определить влияние различных добавок на свойства обычного бетона. В бетонную смесь внесены три вида добавок: желатиновый порошок в качестве связующего, вторичные заполнители и миндальная скорлупа в качестве мелкого и крупного заполнителей. Проведено исследование по определению физико-механических свойств бетона с указанными добавками: прочности на сжатие и растяжение, испытания на ударную нагрузку, на долговечность (водопоглощение) и на глубину проникновения влаги в бетон. Микроструктура бетона изучена с помощью сканирующей электронной микроскопии (SEM) и энергодисперсионной рентгеновской спектроскопии (EDXS). Установлено, что при добавлении 70 кг желатинового порошка на 1 м3 бетона его прочность на сжатие и растяжение увеличилась более чем на 22 %; под действием ударной нагрузки начальное и предельное количество трещин составляет 11 и 129, а начальная и предельная прочность трещинообразования - более 223 и 2346 Дж соответственно. Кроме того, показатели долговечности лучше у бетона с добавлением желатина. Результаты, полученные при помощи SEM, демонстрируют, что пониженная прочность бетона с добавлением миндальной скорлупы связана с трещинами и пустотами между цементной матрицей и миндальной скорлупой. Пустоты в бетоне с желатином выше, чем в обычном бетоне. Структура обычного бетона имеет вид гладких кристаллов, а бетона с желатином - острые и кубические кристаллы. Результаты, полученные с помощью EDXS, показали различие в химическом составе: обычный бетон содержит кремний, тогда как бетон с добавкой желатина в вышеуказанных пропорциях содержит кальций и в нем образуется гель C-S-H