广西建工(Guangxi Construction Engineering Group) is a construction company based in Guangxi, China. They are known for their extensive experience in various construction projects, including infrastructure, residential, and commercial developments.As for the "45 to 90t crane pipe-laying machine," it refers to a specific type of machinery used in construction projects to lay and install pipes. This machine is capable of lifting and placing pipes weighing between 45 to 90 tons.This type of machinery is commonly employed in the construction of pipelines for various purposes, such as water supply, sewage systems, or oil and gas transportation.Given the weight range of the crane pipe-laying machine, it can handle pipes of significant sizes and is usually operated by skilled operators who are trained in the safe and efficient use of this equipment.It's important to note that this information is based on general knowledge about construction equipment and the description provided. For more specific details about Guangxi Construction Engineering Group or their specific machinery, it is recommended to contact the company directly.