The objective of this study was to evaluate the construction, material characterization, initial structural assessment, and cost of a novel jointless Engineered Cementitious Composite Ultra-Thin Whitetopping (ECC-UTW) overlay. After construction, early-age cracks (from less than 0.25 mm to up to 2.54 mm width) were observed in the 101.6-mm (4 in.) jointless ECC-UTW section; yet, the majority of the cracks coincided with areas where fiber clumps were observed during construction and places of heavy instrumentation. On the other hand, no cracks were observed in the 63.5-mm (2.5 in.) jointless ECC-UTW at early ages; yet, when winter arrived, micro-cracks (<0.25 mm in width) developed. These micro-cracks were attributed to the normal functioning of the ductile pseudo strain-hardening (PSH) mechanism of ECC materials. Falling Weight Deflectometer (FWD) evaluation conducted before and after the construction of the UTWs showed a significant reduction in pavement deflection after construction. This deflection reduction was much more substantial for thicker 101.6-mm UTWs; yet, no major difference in deflection reduction was found between the 101.6-mm ECC and the 101.6-mm regular concrete UTW sections. The 28-day compressive and flexural strength of ECC evaluated from field specimens underperformed that of previous studies by 9.6% and 14.8%, respectively; however, deflection capacity slightly outperformed that of previous studies by 4.1%. The flexural performance of the ECC material was vastly superior to that of regular concrete exceeding the flexural strength by 92%. All specimens evaluated in uniaxial tension exhibited a PSH behavior after first-cracking; however, the tensile strength and tensile ductility values obtained underperformed expected values for ECC M3-15% and exhibited substantial variability. Uniaxial tensile test results from field specimens were deemed unreliable. Cost analysis results showed that a cost reduction of 14.8% per lane kilometer is expected by implementing the proposed jointless ECC-UTW system compared to that of the regular jointed concrete UTW. The greatest construction cost savings for utilizing ECC originates from its potential jointless attribute and its reduced thickness.

这项研究的目的是评估新型无接缝工程胶凝复合超薄白面涂料（ECC-UTW）覆盖层的结构，材料特性，初始结构评估和成本。施工后，在101.6毫米（4英寸）无接缝ECC-UTW截面中观察到了早期裂纹（宽度小于0.25毫米至最大2.54毫米）。但是，大多数裂缝与在施工期间和重型仪器安装场所观察到纤维结块的区域重合。另一方面，在早期的63.5毫米（2.5英寸）无缝ECC-UTW中未观察到裂纹。然而，当冬天到来时，出现了微裂纹（宽度<0.25毫米）。这些微裂纹归因于ECC材料的延展性伪应变硬化（PSH）机制的正常运行。UTW施工前后进行的落锤挠度计（FWD）评估显示，施工后路面挠度显着降低。对于较厚的101.6毫米UTW，这种偏转减小的幅度要大得多。但是，在101.6毫米ECC和101.6毫米普通混凝土UTW截面之间，减小挠度没有发现主要差异。野外标本评估的ECC的28天抗压强度和抗弯强度分别比以前的研究低9.6％和14.8％。但是，挠曲能力比以前的研究稍好4.1％。ECC材料的抗弯性能大大超过普通混凝土，超过抗弯强度达92％。所有在单轴拉伸下评估的试样在首次破裂后均表现出PSH行为。但是，获得的拉伸强度和拉伸延展性值不及ECC M3-15％的预期值，并且表现出很大的可变性。现场样品的单轴拉伸试验结果被认为是不可靠的。成本分析结果表明，与常规的联合混凝土UTW相比，通过实施建议的无缝ECC-UTW系统，预计每车道公里成本可降低14.8％。利用ECC可以最大程度地节省建筑成本，这是由于其潜在的无缝连接特性和厚度减小的缘故。与常规的普通混凝土UTW相比，通过实施建议的无接缝ECC-UTW系统，预计每车道公里8％。利用ECC可以最大程度地节省建筑成本，这要归功于其潜在的无接缝属性和减小的厚度。与常规的普通混凝土UTW相比，通过实施建议的无接缝ECC-UTW系统，预计每车道公里8％。利用ECC可以最大程度地节省建筑成本，这要归功于其潜在的无接缝属性和减小的厚度。