本现场测试计划旨在为最终用户提供测试结果，该测试结果可用于对一层、两层或三层涂层系统进行性能判断，以对之前涂漆的钢结构进行维护涂层。本现场测试计划旨在适用于维护涂层，此处定义为在现有涂层上进行清洁和涂漆的实践，该涂层基本上完好无损，但存在需要修复的腐蚀或油漆剥落区域。这种做法通常包括对生锈或退化区域、现有油漆边缘进行局部处理、对整个结构进行动力清洗、为裸露或修复区域涂底漆、在修复区域或整个结构上涂一层中间涂层、在整个结构上涂一层完整面漆的可选步骤，或这些程序的类似变化。 本现场测试计划评估了应用于现有涂漆钢表面的保护涂层的性能，这些表面具有不同程度的表面处理和条件，包括手动工具清洁的表面（SSPC SP 2）、使用常规电动工具清洁的表面（SSPC SP 3）、清洁至裸金属的电动工具表面（SSPC SP 15）和工业喷砂（SSPC SP 14）。如本文所述，在适当的表面处理后，将现场测试计划中的涂层材料应用于现有桥梁或回收桥梁的先前涂漆钢表面，然后每年评估一次，除非另有约定，为期三年。本现场测试计划的所有要素应按照适用的地方、州和国家环境和工人保护法规执行。 本文件中不一定具体提及材料、环境和工人保护要求，因为这些规定广为人知，遵守这些规定是桥梁涂装行业的标准做法。

This field testing program has been established to provide the end user with test results which can be used to make performance judgments on one-, two-, or three-coat systems for maintenance overcoating previously painted steel structures.This field testing program is intended to apply to maintenance overcoating, herein defined as the practice of cleaning and painting over an existing coating which is largely intact but has areas of corrosion or peeling paint in need of repair. This practice usually includes the spot preparation of rusted or degraded areas, feathering edges of existing paint, power washing the entire structure, priming bare or repaired areas, applying an intermediate coat over the repaired areas or entire structure, and the optional step of applying a full topcoat over the entire structure, or a similar variation of these procedures.This field testing program evaluates the performance of protective coatings applied to existing painted steel surfaces with various degrees of surface preparation and condition, including, surfaces hand tool cleaned (SSPC SP 2), surfaces cleaned by conventional power tools (SSPC SP 3), surfaces power tool cleaned to bare metal (SSPC SP 15), and industrial blast (SSPC SP 14).The coating materials in the field testing program are applied to previously painted steel surfaces of existing bridges or salvaged bridge beams after proper surface preparations, as described herein, and thereafter evaluated annually, unless otherwise agreed, for a period of three years.All of the elements of this field testing program shall be performed in accordance with applicable local, state, and national regulations governing environmental and worker protection. Specific references to material, environmental, and worker protection requirements are not necessarily made in this document since these regulations are widely known and compliance with these regulations is standard practice in the bridge painting industry.